Fourth and Fifth Infinitives in Finnish

In Brief

The Finnish fourth infinitive in -minen names an action or activity: lukea “to read” becomes lukeminen “reading.” It is extremely common and behaves much like an ordinary noun. The much rarer fifth infinitive occurs with olla “to be” and means “to be just about to do something”: Olin lähtemäisilläni means “I was about to leave.”

Overview

An infinitive is a verb form that does not by itself show a complete combination of person and tense. Finnish traditionally numbers several infinitive constructions. The forms in this article are called the fourth and fifth infinitives, although modern descriptions often call the -minen form an action noun or verbal noun—a noun made from a verb. That alternative name is helpful: lukeminen can fill many of the same positions in a sentence as an ordinary noun such as kirja “book.”

At B1, the fourth infinitive is immediately useful. Finnish uses -minen to discuss activities, habits, skills, and processes: studying, cooking, travelling, learning. English often uses an -ing form in the same situations, but the match is not automatic: English “-ing” can have several grammatical jobs, while Finnish chooses among -minen, other infinitive forms, and participles according to the sentence.

The fifth infinitive has a much narrower purpose. It presents an event as very close to happening, usually with a sense of “just about to” or “on the verge of.” You will see it less often than ordinary expressions such as aikoa “intend” or olla lähdössä “be leaving/about to leave,” but it is expressive and worth recognizing.

How It Works

The fourth infinitive: verb stem + -minen

The basic -minen form is built from the same stem seen before many Finnish verb endings. Vowel harmony determines whether preceding vowels are back or front vowels, but the ending itself remains -minen.

Dictionary form	Stem seen in the new word	Fourth infinitive	Meaning
puhua	puhu-	puhuminen	speaking
lukea	luke-	lukeminen	reading
syödä	syö-	syöminen	eating
opiskella	opiskele-	opiskeleminen	studying
tarvita	tarvitse-	tarvitseminen	needing
tehdä	teke-	tekeminen	doing, making
juosta	juokse-	juokseminen	running
olla	ole-	oleminen	being

The stem may therefore look different from the dictionary form. It is safer to learn tehdä → tekeminen and juosta → juokseminen as stem relationships rather than simply removing the final letter and adding -minen.

It declines like a noun

To decline a word means to change its ending to show its role in the sentence. Words in -minen follow the same pattern as Finnish nouns in -nen: outside the nominative singular, -nen normally changes to -se-. This is the pattern also found in nainen → naisen.

Case and basic meaning	Form of lukeminen	Example meaning
nominative, basic form	lukeminen	reading
genitive, “of” form	lukemisen	of reading
partitive, partial object/after certain verbs	lukemista	reading
inessive, “in/while doing”	lukemisessa	in reading
elative, “from/about”	lukemisesta	from/about reading
illative, “into”	lukemiseen	into reading
adessive, “with/by”	lukemisella	by means of reading
abessive, “without”	lukematta	without reading

That last form needs care. Lukematta can formally belong to the noun’s case pattern, but it is also traditionally analyzed as the third infinitive abessive. For practical learning, recognize the highly productive meaning “without doing”: Hän lähti hyvästelemättä “He/She left without saying goodbye.”

Because the fourth infinitive is noun-like, adjectives modifying it take matching forms: säännöllinen liikkuminen “regular exercise,” säännöllisestä liikkumisesta “about/from regular exercise.” It can also be the subject (the part the sentence is about), object (what an action affects), or complement of a postposition.

Participants around a -minen word

A genitive form—often corresponding to English “of” or a possessive—can identify the person doing the activity:

• lasten leikkiminen — the children’s playing / the children playing
• hänen laulamisensa — his/her singing
• minun lähtemiseni — my leaving

The possessive suffix in laulamisensa or lähtemiseni reinforces whose action it is. In everyday Finnish, the exact choice between a separate genitive pronoun, a possessive suffix, or both depends on the construction and register.

The thing affected by an action is also commonly put in the genitive inside an action-noun phrase:

• kirjan lukeminen — reading the book
• uuden kielen oppiminen — learning a new language

Do not treat this as a mechanical replacement for every English “-ing” phrase. The whole -minen expression is a noun phrase, and Finnish case rules apply to the surrounding sentence.

The fifth infinitive: -maisilla- plus a possessive suffix

The fifth infinitive is formed with -maisilla- (or its front-vowel counterpart -mäisillä-) and a possessive suffix, an ending that identifies the person connected with the action. It is used with the verb olla:

subject + olla + verb stem + -maisilla/-mäisillä + possessive suffix

Person	Example with lähteä	English
minä	olen lähtemäisilläni	I am about to leave
sinä	olet lähtemäisilläsi	you are about to leave
hän	on lähtemäisillään	he/she is about to leave
me	olemme lähtemäisillämme	we are about to leave
te	olette lähtemäisillänne	you are about to leave
he	ovat lähtemäisillään	they are about to leave

The suffix is essential: it agrees with the person who is on the verge of acting. In the third person, both singular and plural use -an/-än after the long vowel created at the end: -llaan/-llään.

The verb olla carries tense, negation, and questions:

• Olen nukahtamaisillani. — I am about to fall asleep.
• Olin nukahtamaisillani. — I was about to fall asleep.
• En ollut nukahtamaisillani. — I was not about to fall asleep.
• Olitko nukahtamaisillasi? — Were you about to fall asleep?

A past-tense fifth infinitive often implies a near event that did not happen, but context decides this. Olin kaatumaisillani naturally suggests “I nearly fell,” whereas the next sentence can explain whether the action eventually happened.

Examples in Context

Finnish	English	Note
Lukeminen on hauskaa.	Reading is fun.	The activity is the subject.
Oppiminen vie aikaa.	Learning takes time.	A process named with -minen.
Juokseminen on terveellistä.	Running is healthy.	General activity.
Pidän ruoanlaitosta, mutta en siivoamisesta.	I like cooking, but not cleaning.	Pitää takes the elative -sta/-stä.
Aloitin suomen opiskelun viime vuonna.	I started studying Finnish last year.	The action noun is the object; opiskelu is a common shorter lexical noun related to opiskella.
Uuden kielen oppiminen vaatii kärsivällisyyttä.	Learning a new language requires patience.	The affected thing is uuden kielen.
Lasten nauraminen kuului pihalta.	The children’s laughter could be heard from the yard.	Lasten identifies who was laughing.
Keskustelimme etätyön tekemisestä.	We discussed working remotely.	The elative follows keskustella jostakin.
Säännöllisellä harjoittelemisella saa tuloksia.	Regular practice produces results.	The adessive presents a means.
Hänen myöhästymisensä yllätti meidät.	His/Her being late surprised us.	A possessive suffix marks the person involved.
Olen lähtemäisilläni, joten puhutaan nopeasti.	I’m just about to leave, so let’s talk quickly.	Present fifth infinitive.
Olin nukahtamaisillani, kun puhelin soi.	I was about to fall asleep when the phone rang.	An interruption prevents or delays the event.
Lasi oli putoamaisillaan pöydältä.	The glass was about to fall off the table.	The subject need not be a person.
He olivat luovuttamaisillaan, mutta jatkoivat silti.	They were on the verge of giving up, but continued anyway.	The following clause confirms that they did not give up.
Oletko sanomaisillasi jotain?	Are you about to say something?	Question formed by adding -ko to olet.

Common Mistakes

Using the dictionary form before -minen

• Wrong: lukeaminen
• Right: lukeminen
• Why: Build the word from the appropriate verb stem, not by attaching -minen to the full dictionary form. Learn common stem changes such as lukea → lukeminen, tehdä → tekeminen, and juosta → juokseminen.

Keeping -nen throughout the case forms

• Wrong: Pidän lukeminenstä.
• Right: Pidän lukemisesta.
• Why: Like other nouns in -nen, the form uses a -se- stem when case endings are added: lukeminen → lukemisen → lukemisesta.

Translating every English -ing form with -minen

• Wrong: Olen lukeminen kirjaa.
• Right: Luen kirjaa. or Olen lukemassa kirjaa.
• Why: English “I am reading” is a finite verb construction, not the name of an activity. Finnish normally uses the present tense luen; olla + -massa emphasizes being engaged in the activity. -minen is noun-like: Lukeminen rentouttaa “Reading relaxes me.”

Omitting the possessive suffix from the fifth infinitive

• Wrong: Olin lähtemäisillä.
• Right: Olin lähtemäisilläni.
• Why: The fifth infinitive conventionally includes a possessive suffix matching the subject: -ni, -si, -an/-än, -mme, -nne.

Making the fifth-infinitive form carry the tense

• Wrong: trying to add a past-tense ending to lähtemäisilläni
• Right: Olin lähtemäisilläni.
• Why: Olla carries present or past tense. The infinitive part stays the same.

Confusing intention with immediate imminence

• Misleading: Olen matkustamaisillani Japaniin ensi vuonna.
• Natural for a plan: Aion matkustaa Japaniin ensi vuonna.
• Why: The fifth infinitive presents an action as being right on the verge of happening. A plan for next year calls for aikoa “intend,” not normally -maisillaan.

Usage Notes

The fourth infinitive is productive, but a language may have an established noun that speakers prefer. Alongside opiskeleminen “the act of studying,” Finnish commonly has opiskelu “studying/studies”; alongside harjoitteleminen, there is harjoittelu. The -minen form puts the action itself clearly in focus, while a shorter established noun may refer more broadly to the activity, practice, or field. The difference is often one of idiom rather than a strict change of meaning.

English allows “-ing” forms in a very wide range of constructions. Finnish separates these jobs more sharply. Compare lukeminen “reading as an activity,” olen lukemassa “I am (engaged in) reading,” and lukemalla “by reading.” They come from the same verb but are not interchangeable.

The fifth infinitive is grammatical but relatively uncommon. In conversation, speakers often choose a more transparent alternative:

Fifth infinitive	Common alternative	Typical difference
Olin lähtemäisilläni.	Olin juuri lähdössä.	Both mean “I was just about to leave”; the latter is very common.
Hän oli kaatumaisillaan.	Hän oli vähällä kaatua.	Both can mean “He/She nearly fell.”
Vauva on nukahtamaisillaan.	Vauva nukahtaa ihan pian.	The alternative says the baby will fall asleep very soon.

Using the rarer form can give the moment a vivid “on the brink” quality. It is particularly natural when something interrupts the action or when the speaker describes a narrowly avoided event.

Beyond the Basics / Advanced Use

The fourth infinitive in obligation constructions

Traditional grammar also associates the fourth infinitive with constructions expressing necessity. A sentence such as Sinun on lähteminen literally has a genitive experiencer sinun and a -minen form; it means roughly “You must leave.” In present-day language, Sinun täytyy lähteä or Sinun on lähdettävä is usually more neutral. The -minen version can sound emphatic, old-fashioned, or deliberately forceful.

A related negative pattern remains useful:

• Sinne ei ole menemistä. — You must not go there / There is no going there.
• Tässä säässä ei ole uimista. — There is no swimming in this weather.

Here the partitive -mista/-mistä form presents an activity as unavailable, impossible, or forbidden. The exact English wording depends heavily on context.

Action nouns can become established vocabulary

Some -minen forms develop meanings beyond a purely transparent “act of doing.” Context and dictionaries become important when a form is lexicalized—that is, established as a vocabulary item with its own conventional meaning. Even when the meaning is fully transparent, long chains of action nouns can make formal writing heavy. Finnish often rewrites such chains with a finite clause when clarity matters, just as good English avoids piling up too many abstract nouns.

Near event, interrupted event, and actual result

The fifth infinitive locates the subject immediately before an event; it does not logically state the final outcome. Context often creates one of three readings:

1. Imminent: Juna on lähtemäisillään. — The train is about to leave.
2. Interrupted: Olin vastaamaisillani, kun hän vaihtoi aihetta. — I was about to answer when he changed the subject.
3. Narrowly avoided: Auto oli törmäämäisillään puuhun. — The car nearly hit a tree.

In past contexts, English frequently prefers “nearly” for the third reading. Do not infer the outcome from the form alone; look at the surrounding clauses.

Practice Tips

1. Build families, not isolated forms. Take five familiar verbs and write the dictionary form, -minen form, genitive, and elative: lukea → lukeminen → lukemisen → lukemisesta. Include one irregular-looking stem such as tehdä → tekeminen.
2. Sort English -ing examples by job. For each sentence, ask whether “-ing” names an activity (Uiminen on kivaa), describes an action in progress (Olen uimassa), or expresses a method (Opin uimalla). This prevents overusing -minen.
3. Practice the fifth infinitive through mini-scenes. Pair an almost completed action with an interruption: Olin lähtemäisilläni, kun... or Hän oli nukahtamaisillaan, mutta.... Change the subject so that you rehearse all possessive suffixes.

Related Concepts

• Prerequisite: Infinitive Forms — introduces the wider Finnish infinitive system and helps distinguish these forms from other infinitives.