languages.grammar.heading

掌握葡萄牙语的Subject Pronouns（Pronomes do Sujeito）是有效沟通的基础要素之一。这是 A1（入门）级别的学习内容。Personal subject pronouns (eu, tu, ele/ela/você, nós, vós, eles/elas/vocês). Note: você/vocês is common in Brazil (replacing tu in most regions), while tu is common in Portugal.

对于葡萄牙语学习者来说，Gender of Nouns（Género dos Substantivos）是一个非常重要的语法概念。这是 A1（入门）级别的学习内容。Grammatical gender (masculine/feminine) of Portuguese nouns. Most nouns ending in -o are masculine, -a are feminine. Exceptions: o dia, o problema, a mão, a foto.

在葡萄牙语学习中，Plural Formation（Formação do Plural）是语法学习中的关键内容。这是 A1（入门）级别的学习内容。Regular plural adds -s to vowels. Words ending in consonants add -es. Special: -ão→-ões/-ães/-ãos, -al/-el/-ol→-ais/-éis/-óis, -m→-ns.

学习葡萄牙语时，Definite Articles（Artigos Definidos）是语言基础的重要组成部分。这是 A1（入门）级别的学习内容。Definite articles (o, a, os, as) agree in gender and number with the noun. Used more often than in English (with possessives, proper nouns in Brazil).

葡萄牙语的Indefinite Articles（Artigos Indefinidos）在日常交流中扮演着重要角色。这是 A1（入门）级别的学习内容。Indefinite articles (um, uma, uns, umas) meaning 'a/an' (singular) or 'some' (plural). Often omitted with professions after ser.

掌握葡萄牙语的Ser (to be) - Present（O Verbo Ser - Presente）是有效沟通的基础要素之一。这是 A1（入门）级别的学习内容。Irregular verb 'ser' (sou, és, é, somos, sois, são) for identity, origin, profession, time, characteristics. Essential distinction from 'estar'.

对于葡萄牙语学习者来说，Estar (to be) - Present（O Verbo Estar - Presente）是一个非常重要的语法概念。这是 A1（入门）级别的学习内容。Irregular verb 'estar' (estou, estás, está, estamos, estais, estão) for location, temporary states, feelings, progressive tenses, and results of actions.

在葡萄牙语学习中，Ser vs Estar - Basics（Ser vs Estar - Básico）是语法学习中的关键内容。这是 A1（入门）级别的学习内容。Basic distinction: ser for permanent/inherent qualities, estar for temporary states/locations. Some adjectives change meaning: ser rico (wealthy) vs estar rico (delicious).

学习葡萄牙语时，Ter (to have)（O Verbo Ter）是语言基础的重要组成部分。这是 A1（入门）级别的学习内容。Irregular verb 'ter' (tenho, tens, tem, temos, tendes, têm). Used for possession and as auxiliary in compound tenses. Also in expressions: ter fome, ter sede, ter medo, ter razão.

葡萄牙语的Regular -AR Verbs（Verbos Regulares em -AR）在日常交流中扮演着重要角色。这是 A1（入门）级别的学习内容。Present tense conjugation of regular -ar verbs (falar, trabalhar, estudar, comprar). Largest verb class. Endings: -o, -as, -a, -amos, -ais, -am.

掌握葡萄牙语的Regular -ER Verbs（Verbos Regulares em -ER）是有效沟通的基础要素之一。这是 A1（入门）级别的学习内容。Present tense conjugation of regular -er verbs (comer, beber, escrever, viver). Endings: -o, -es, -e, -emos, -eis, -em.

对于葡萄牙语学习者来说，Regular -IR Verbs（Verbos Regulares em -IR）是一个非常重要的语法概念。这是 A1（入门）级别的学习内容。Present tense conjugation of regular -ir verbs (partir, abrir, assistir). Endings: -o, -es, -e, -imos, -is, -em.

在葡萄牙语学习中，Ir (to go)（O Verbo Ir）是语法学习中的关键内容。这是 A1（入门）级别的学习内容。Highly irregular verb 'ir' (vou, vais, vai, vamos, ides, vão). Used for motion and to form near future (ir + infinitive). Takes preposition 'a' before destinations.

学习葡萄牙语时，Fazer (to do/make)（O Verbo Fazer）是语言基础的重要组成部分。这是 A1（入门）级别的学习内容。Irregular verb 'fazer' (faço, fazes, faz, fazemos, fazeis, fazem) with weather expressions (faz calor/frio) and common phrases (fazer desporto, fazer anos).

葡萄牙语的Poder (can/to be able)（O Verbo Poder）在日常交流中扮演着重要角色。这是 A1（入门）级别的学习内容。Irregular verb 'poder' (posso, podes, pode, podemos, podeis, podem). Expresses ability, permission, or possibility + infinitive.

掌握葡萄牙语的Querer (to want)（O Verbo Querer）是有效沟通的基础要素之一。这是 A1（入门）级别的学习内容。Irregular verb 'querer' (quero, queres, quer, queremos, quereis, querem). Expresses desire or wish. Used with infinitive or noun.

对于葡萄牙语学习者来说，Reflexive Verbs（Verbos Reflexivos）是一个非常重要的语法概念。这是 A1（入门）级别的学习内容。Verbs with reflexive pronouns (me, te, se, nos, vos, se): chamar-se, levantar-se, deitar-se, vestir-se. Pronoun placement varies by sentence type.

在葡萄牙语学习中，Há (there is/are)（Há Existencial）是语法学习中的关键内容。这是 A1（入门）级别的学习内容。Impersonal 'há' for existence ('there is/there are'). Also for time expressions (há dois anos = two years ago / for two years). Invariable form.

学习葡萄牙语时，Basic Negation（Negação Básica）是语言基础的重要组成部分。这是 A1（入门）级别的学习内容。Negation with 'não' before the verb. Double negatives are standard: não...nada, não...ninguém, não...nunca. Unlike Spanish, single negative word after verb doesn't negate alone.

葡萄牙语的Regular Adjectives（Adjetivos Regulares）在日常交流中扮演着重要角色。这是 A1（入门）级别的学习内容。Adjective agreement: -o/-a/-os/-as for most adjectives. Two-form adjectives (-e, -l, -z) only change for plural. Most adjectives follow the noun.

掌握葡萄牙语的Adjective Position（Posição dos Adjetivos）是有效沟通的基础要素之一。这是 A1（入门）级别的学习内容。Most adjectives follow the noun, but some common ones precede: bom, mau, grande, pequeno, novo, velho. Some change meaning by position (grande homem vs homem grande).

对于葡萄牙语学习者来说，Possessive Adjectives（Adjetivos Possessivos）是一个非常重要的语法概念。这是 A1（入门）级别的学习内容。Possessives agree with possessed noun: meu/minha/meus/minhas, teu/tua/teus/tuas, seu/sua/seus/suas, nosso/nossa/nossos/nossas. In Brazil, 'seu' often replaced by 'dele/dela'.

在葡萄牙语学习中，Demonstrative Adjectives（Adjetivos Demonstrativos）是语法学习中的关键内容。这是 A1（入门）级别的学习内容。Three-level system: este/esta (near speaker), esse/essa (near listener), aquele/aquela (far from both). Contractions with prepositions: deste, neste, naquele.

学习葡萄牙语时，Prepositions of Place（Preposições de Lugar）是语言基础的重要组成部分。这是 A1（入门）级别的学习内容。Basic location prepositions: em (in/on/at), de (from/of), a (to), com (with), sem (without), entre (between), sobre (on/about), debaixo de (under), em frente de (in front of), atrás de (behind).

葡萄牙语的Contractions (Preposition + Article)（Contrações）在日常交流中扮演着重要角色。这是 A1（入门）级别的学习内容。Mandatory contractions: de + o = do, em + a = na, a + o = ao, por + o = pelo. Also with demonstratives: de + este = deste, em + aquele = naquele.

掌握葡萄牙语的Basic Questions（Perguntas Básicas）是有效沟通的基础要素之一。这是 A1（入门）级别的学习内容。Question words: quem (who), o que/que (what), onde (where), quando (when), como (how), porquê/por que (why). Word order often unchanged, marked by intonation.

对于葡萄牙语学习者来说，Quantity & Selection Questions（Perguntas de Quantidade e Seleção）是一个非常重要的语法概念。这是 A1（入门）级别的学习内容。Question words for quantity: quanto/a/os/as (how much/many), qual/quais (which/what). Quanto agrees in gender/number with the noun.

在葡萄牙语学习中，Cardinal Numbers（Números Cardinais）是语法学习中的关键内容。这是 A1（入门）级别的学习内容。Cardinal numbers 0-100. Um/uma agrees in gender. Numbers 16-19 can be written as one word (dezasseis). Cem (100) vs cento (101+).

学习葡萄牙语时，Ordinal Numbers（Números Ordinais）是语言基础的重要组成部分。这是 A1（入门）级别的学习内容。Ordinal numbers: primeiro, segundo, terceiro, quarto, quinto, sexto, sétimo, oitavo, nono, décimo. Agree in gender/number. Written abbreviated: 1.º/1.ª

葡萄牙语的Time & Dates（As Horas e a Data）在日常交流中扮演着重要角色。这是 A1（入门）级别的学习内容。Telling time (Que horas são? É uma hora. São duas horas.), days of the week, months, expressing dates. Uses definite article with days and months.

掌握葡萄牙语的Frequency & Time Adverbs（Advérbios de Frequência e Tempo）是有效沟通的基础要素之一。这是 A1（入门）级别的学习内容。Adverbs of frequency (sempre, muitas vezes, às vezes, raramente, nunca) and time (hoje, amanhã, ontem, agora, depois, primeiro, então).

对于葡萄牙语学习者来说，Place Adverbs（Advérbios de Lugar）是一个非常重要的语法概念。这是 A1（入门）级别的学习内容。Adverbs of place: aqui/cá (here), aí (there near you), ali/lá (there far), perto (near), longe (far), dentro (inside), fora (outside), em cima (up), em baixo (down).

在葡萄牙语学习中，Muito/Pouco（Muito e Pouco）是语法学习中的关键内容。这是 A1（入门）级别的学习内容。Quantity words: muito/a/os/as and pouco/a/os/as agree with nouns; as adverbs (with verbs/adjectives), they're invariable. Muito = very/much, pouco = little/few.

学习葡萄牙语时，Direct Object Pronouns（Pronomes de Objeto Direto）是语言基础的重要组成部分。这是 A1（入门）级别的学习内容。Direct object pronouns (me, te, o/a, nos, vos, os/as) replace direct objects. Position varies: usually after verb in Portugal (vejo-te), before in Brazil (te vejo).

葡萄牙语的Indirect Object Pronouns（Pronomes de Objeto Indireto）在日常交流中扮演着重要角色。这是 A1（入门）级别的学习内容。Indirect object pronouns (me, te, lhe, nos, vos, lhes) for 'to/for someone'. Lhe = to him/her (formal you), lhes = to them. Position rules same as direct pronouns.

掌握葡萄牙语的Gostar (to like)（O Verbo Gostar）是有效沟通的基础要素之一。这是 A1（入门）级别的学习内容。Regular verb 'gostar' always followed by 'de': gostar de + noun/infinitive. Unlike Spanish gustar, it conjugates normally with subject doing the liking.

对于葡萄牙语学习者来说，Basic Conjunctions（Conjunções Básicas）是一个非常重要的语法概念。这是 A1（入门）级别的学习内容。Common coordinating conjunctions: e (and), ou (or), mas (but), porém (however), porque (because), então (so), portanto (therefore).

在葡萄牙语学习中，Preterite (Pretérito Perfeito)（Pretérito Perfeito Simples）是语法学习中的关键内容。这是 A2（初级）级别的学习内容。Simple past for completed actions. Regular endings: -AR (-ei, -aste, -ou, -ámos, -astes, -aram), -ER/-IR (-i, -este, -eu/-iu, -emos/-imos, -estes/-istes, -eram/-iram).

学习葡萄牙语时，Irregular Preterites（Pretéritos Irregulares）是语言基础的重要组成部分。这是 A2（初级）级别的学习内容。Common irregular preterites: ser/ir (fui), estar (estive), ter (tive), fazer (fiz), dizer (disse), vir (vim), poder (pude), pôr (pus), saber (soube), trazer (trouxe).

葡萄牙语的Imperfect Tense（Pretérito Imperfeito）在日常交流中扮演着重要角色。这是 A2（初级）级别的学习内容。Past tense for habitual actions, descriptions, ongoing states. Regular endings: -AR (-ava, -avas, -ava, -ávamos...), -ER/-IR (-ia, -ias, -ia, -íamos...). Few irregulars: ser, ter, vir, pôr.

掌握葡萄牙语的Near Future (ir + inf)（Futuro Próximo）是有效沟通的基础要素之一。这是 A2（初级）级别的学习内容。Immediate future formed with ir + infinitive. Expresses planned or imminent actions. Vou comer, vais estudar, vai chover.

对于葡萄牙语学习者来说，Present Progressive（Estar + Gerúndio）是一个非常重要的语法概念。这是 A2（初级）级别的学习内容。Progressive with estar + gerund (-ando/-endo/-indo). For actions in progress. Brazil uses estar + gerund; Portugal often uses estar a + infinitive.

在葡萄牙语学习中，Comparisons（Os Comparativos）是语法学习中的关键内容。这是 A2（初级）级别的学习内容。Comparative forms: mais...do que (more than), menos...do que (less than), tão...como (as...as), tanto/a/os/as...como (as much/many as). Irregulars: melhor, pior, maior, menor.

学习葡萄牙语时，Imperative Mood（Imperativo）是语言基础的重要组成部分。这是 A2（初级）级别的学习内容。Commands: tu form from present (fala! come!), você/vocês use subjunctive forms. Negative uses não + subjunctive. Pronouns attach to affirmative commands.

葡萄牙语的Relative Pronouns: que, quem（Pronomes Relativos: que, quem）在日常交流中扮演着重要角色。这是 A2（初级）级别的学习内容。Basic relative pronouns: que (who/which/that - most common), quem (who - for people, after prepositions). Que is invariable.

掌握葡萄牙语的Combined Object Pronouns（Pronomes Combinados）是有效沟通的基础要素之一。这是 A2（初级）级别的学习内容。Combining indirect + direct pronouns: me + o = mo, te + a = ta, lhe + os = lhos. Contractions vary between Portugal and Brazil usage.

对于葡萄牙语学习者来说，Reflexive Verbs in Past（Verbos Reflexivos no Passado）是一个非常重要的语法概念。这是 A2（初级）级别的学习内容。Reflexive verbs in preterite and imperfect. Pronoun placement rules apply. In Brazil, pronoun often precedes verb; in Portugal, follows (with hyphen).

在葡萄牙语学习中，Simple Future（Futuro Simples）是语法学习中的关键内容。这是 B1（中级）级别的学习内容。Future tense formed with infinitive + endings (-ei, -ás, -á, -emos, -eis, -ão). Irregular stems: fazer→far-, dizer→dir-, trazer→trar-. Often replaced by ir + infinitive in speech.

学习葡萄牙语时，Conditional（Condicional）是语言基础的重要组成部分。这是 B1（中级）级别的学习内容。Conditional formed with infinitive + imperfect endings of haver (-ia, -ias, -ia, -íamos, -íeis, -iam). Same irregular stems as future. Used for polite requests, hypotheticals.

葡萄牙语的Preterite vs Imperfect（Perfeito vs Imperfeito）在日常交流中扮演着重要角色。这是 B1（中级）级别的学习内容。Contrast between tenses: perfeito for completed actions at specific times, imperfeito for background, habits, descriptions. Often used together in narratives.

掌握葡萄牙语的Present Subjunctive（Conjuntivo Presente）是有效沟通的基础要素之一。这是 B1（中级）级别的学习内容。Subjunctive mood for wishes, doubts, emotions, necessity after que. Formed from eu stem: -AR (-e, -es, -e, -emos, -eis, -em), -ER/-IR (-a, -as, -a, -amos, -ais, -am).

对于葡萄牙语学习者来说，Subjunctive Triggers（Usos do Conjuntivo）是一个非常重要的语法概念。这是 B1（中级）级别的学习内容。Expressions requiring subjunctive: querer que, esperar que, é necessário que, é possível que, oxalá, antes que, para que, embora, quando (future).

在葡萄牙语学习中，Pluperfect Tense（Mais-que-perfeito）是语法学习中的关键内容。这是 B1（中级）级别的学习内容。Past-before-past: compound form (tinha + participle) more common than simple form. For actions completed before another past action.

学习葡萄牙语时，Superlative（O Superlativo）是语言基础的重要组成部分。这是 B1（中级）级别的学习内容。Superlative forms: o/a/os/as mais/menos + adjective (+ de). Irregular: o melhor (the best), o pior (the worst), o maior (the biggest), o menor (the smallest). Absolute superlative: -íssimo/a.

葡萄牙语的Relative Pronouns: onde, cujo（Pronomes Relativos: onde, cujo）在日常交流中扮演着重要角色。这是 B1（中级）级别的学习内容。Additional relative pronouns: onde (where), cujo/a/os/as (whose - agrees with possessed noun). O qual/a qual for formal contexts with prepositions.

掌握葡萄牙语的Passive Voice（Voz Passiva）是有效沟通的基础要素之一。这是 B1（中级）级别的学习内容。Passive formed with ser + past participle (agrees with subject). Agent introduced by por. Also passive se construction: fala-se português.

对于葡萄牙语学习者来说，Indirect Speech（Discurso Indireto）是一个非常重要的语法概念。这是 B1（中级）级别的学习内容。Reported speech with verbs like dizer, perguntar, responder. Tense backshift when reporting verb is past. Que for statements, se for yes/no questions.

在葡萄牙语学习中，Personal Infinitive（Infinitivo Pessoal）是语法学习中的关键内容。这是 B1（中级）级别的学习内容。Unique Portuguese feature: infinitive that conjugates for person (-es, -mos, -des, -em). Clarifies subject in infinitive clauses. É importante estudarmos.

学习葡萄牙语时，Impersonal Constructions（Construções Impessoais）是语言基础的重要组成部分。这是 B1（中级）级别的学习内容。Impersonal expressions: é preciso/necessário + infinitive or que + subjunctive. É possível, é importante. Há que + infinitive (one must).

葡萄牙语的Conditional Sentences (Se clauses)（Orações Condicionais）在日常交流中扮演着重要角色。这是 B1（中级）级别的学习内容。If-then constructions: Se + present → future/imperative (real), Se + imperfect subjunctive → conditional (unreal present). Caso, a menos que.

掌握葡萄牙语的Ser vs Estar - Advanced（Ser vs Estar - Avançado）是有效沟通的基础要素之一。这是 B1（中级）级别的学习内容。Complex ser/estar distinctions: adjectives changing meaning, passive ser vs resultant estar, ser casado vs estar casado (regional).

对于葡萄牙语学习者来说，Imperfect Subjunctive（Conjuntivo Imperfeito）是一个非常重要的语法概念。这是 B2（中高级）级别的学习内容。Past subjunctive from third person plural preterite: -sse endings (falasse, comesse, partisse). Used after past tense verbs, in unreal conditionals, with oxalá for unlikely wishes.

在葡萄牙语学习中，Future Subjunctive（Conjuntivo Futuro）是语法学习中的关键内容。这是 B2（中高级）级别的学习内容。Unique to Portuguese: future subjunctive for uncertain future. From third person plural preterite stem: -ar→-ar, -er/-ir→-er/-ir. Used with quando, se, enquanto, assim que for future.

学习葡萄牙语时，Perfect Subjunctive（Conjuntivo Perfeito）是语言基础的重要组成部分。这是 B2（中高级）级别的学习内容。Present perfect subjunctive: present subjunctive of ter (tenha, tenhas...) + past participle. For past actions in subjunctive contexts when main verb is present.

葡萄牙语的Compound Conditional（Condicional Composto）在日常交流中扮演着重要角色。这是 B2（中高级）级别的学习内容。Conditional perfect: conditional of ter (teria, terias...) + past participle. For hypotheticals about the past, regrets. Teria querido, teriam vindo.

掌握葡萄牙语的Past Conditional Sentences（Condicionais Passadas）是有效沟通的基础要素之一。这是 B2（中高级）级别的学习内容。Third conditional: Se + pluperfect subjunctive → conditional perfect. For contrary-to-fact past situations. Mixed conditionals also possible.

对于葡萄牙语学习者来说，Pluperfect Subjunctive（Mais-que-perfeito Composto do Conjuntivo）是一个非常重要的语法概念。这是 B2（中高级）级别的学习内容。Past perfect subjunctive: imperfect subjunctive of ter (tivesse) + past participle. For past hypotheticals, wishes about the past.

在葡萄牙语学习中，Future Perfect（Futuro Composto）是语法学习中的关键内容。这是 B2（中高级）级别的学习内容。Future perfect: future of ter (terei, terás...) + past participle. For actions completed before a future point, or for probability about past events.

学习葡萄牙语时，Pronoun Placement（Colocação dos Pronomes）是语言基础的重要组成部分。这是 B2（中高级）级别的学习内容。Complex pronoun placement rules: proclisis (before verb) after negation, question words, subordinate clauses; mesoclisis (within verb) in future/conditional; enclisis (after) otherwise.

葡萄牙语的Adverbs in -mente（Advérbios em -mente）在日常交流中扮演着重要角色。这是 B2（中高级）级别的学习内容。Formation: feminine adjective + -mente (lentamente, rapidamente). With multiple adverbs, only last takes -mente (lenta e cuidadosamente).

掌握葡萄牙语的Simple Pluperfect（Mais-que-perfeito Simples）是有效沟通的基础要素之一。这是 C1（高级）级别的学习内容。Literary pluperfect: single verb form from preterite stem + -ra endings (falara, comera, partira). Used in formal writing, literature. Often replaced by compound form in speech.

对于葡萄牙语学习者来说，Personal Infinitive - Advanced（Infinitivo Pessoal Avançado）是一个非常重要的语法概念。这是 C1（高级）级别的学习内容。Complex uses of personal infinitive: compound forms (ter + participle), passive forms (ser + participle), in place of subjunctive in certain contexts.

在葡萄牙语学习中，Sequence of Tenses（Concordância dos Tempos）是语法学习中的关键内容。这是 C1（高级）级别的学习内容。Complex tense agreement in subordinate clauses. Main clause in past → subordinate in imperfect/pluperfect subjunctive or future subjunctive for still-future events.

学习葡萄牙语时，Formal Register（Registo Formal）是语言基础的重要组成部分。这是 C1（高级）级别的学习内容。Formal vocabulary and constructions: mediante, não obstante, em virtude de, no âmbito de, em conformidade com. Business and legal language patterns.

葡萄牙语的Nominalization（Nominalização）在日常交流中扮演着重要角色。这是 C1（高级）级别的学习内容。Converting verbs/adjectives to nouns for formal style: desenvolver→desenvolvimento, possível→possibilidade. Common suffixes: -ção, -mento, -dade, -ncia.

掌握葡萄牙语的Emphatic Structures（Estruturas de Ênfase）是有效沟通的基础要素之一。这是 C1（高级）级别的学习内容。Emphatic constructions: é que (foi Maria que fez), o que...é (o que quero é paz), clivagem (quem fez foi ele), topicalization.

对于葡萄牙语学习者来说，Diminutives & Augmentatives（Diminutivos e Aumentativos）是一个非常重要的语法概念。这是 C1（高级）级别的学习内容。Affective suffixes: -inho/a (affection, smallness), -zinho/a (after nasal/stressed vowel), -ão/ona (augmentative), -aço (augmentative/blow). Regional variation.

在葡萄牙语学习中，Brazilian vs European Portuguese（Variação Brasil/Portugal）是语法学习中的关键内容。这是 C2（精通）级别的学习内容。Systematic differences: pronoun placement, use of estar a vs gerund, você vs tu, vocabulary (autocarro/ônibus, telemóvel/celular), pronunciation patterns.

学习葡萄牙语时，Colloquial Register（Registo Coloquial）是语言基础的重要组成部分。这是 C2（精通）级别的学习内容。Informal spoken Portuguese: interjections (pá!, bué, fixe, giro - PT; cara, legal, mano - BR), gíria, truncation, filler words.

葡萄牙语的Discourse Connectors（Conectores do Discurso）在日常交流中扮演着重要角色。这是 C2（精通）级别的学习内容。Advanced connectors for argumentation: no entanto, todavia, contudo, por conseguinte, com efeito, é de salientar que, cumpre referir.

掌握葡萄牙语的Rhetorical Devices（Recursos Retóricos）是有效沟通的基础要素之一。这是 C2（精通）级别的学习内容。Stylistic constructions: lítotes (understatement), hipérbole, pergunta retórica, quiasmo, anáfora. Sentence fragmenting for effect.

对于葡萄牙语学习者来说，Administrative Language（Linguagem Administrativa）是一个非常重要的语法概念。这是 C2（精通）级别的学习内容。Bureaucratic and legal Portuguese: passive constructions, nominalization, technical terms, formal closings, fixed expressions in official documents.