Modal Verbs in Welsh

In Brief

Welsh usually expresses can, must, and want with a phrase rather than with a single auxiliary like English can or must. The essential patterns are dw i'n gallu + verb-noun (“I can…”), (mae) rhaid i fi + verb-noun (“I must…”), and dw i eisiau + noun or verb-noun (“I want…”). Notice that gallu and gorfod take yn, but eisiau normally does not.

Overview

Modal verbs add meanings such as ability, obligation, permission, or desire to another action. In “I can swim,” for example, can tells us that swimming is possible; in “I must leave,” must presents leaving as necessary. Welsh expresses these ideas through several different constructions, not through one uniform set of modal auxiliaries.

This is an A1 topic because a few reusable frames let you handle many everyday situations: saying what you can do, explaining what you have to do, asking for help, and stating what you want. The foundation is the present tense of bod (“to be”): dw i, wyt ti, mae e/hi, dyn ni, dych chi, and maen nhw. Welsh then combines a form of bod with a verb-noun (the basic dictionary form used where English often uses “to…”), such as gallu (“to be able”), gorfod (“to have to”), or mynd (“to go”).

English-speaking learners need to resist translating one word at a time. English must, for instance, can correspond to rhaid i… or gorfod, and English want is commonly expressed with the unusual pattern bod + eisiau without yn. Learn the whole frame around each word.

How It Works

The four core frames

Meaning	Welsh frame	Basic example	Natural English
ability	form of bod + yn gallu + verb-noun	Dw i'n gallu nofio.	I can swim.
obligation, impersonal	(mae) rhaid i + person + verb-noun	Mae rhaid i fi fynd.	I must go.
obligation, personal	form of bod + yn gorfod + verb-noun	Dw i'n gorfod mynd.	I have to go.
desire	form of bod + eisiau/moyn + noun or verb-noun	Dw i eisiau coffi.	I want coffee.

The apostrophe in i'n represents a shortened vowel: dw i yn gallu becomes the normal spoken and written form dw i'n gallu. By contrast, there is no missing apostrophe in dw i eisiau: this construction normally has no yn.

Ability with gallu

Gallu literally carries the idea of “being able.” Use the appropriate present form of bod, then yn gallu, then the action in its verb-noun form.

Person	Pattern with gallu mynd	Meaning
I	Dw i'n gallu mynd.	I can go.
you, familiar singular	Rwyt ti'n gallu mynd.	You can go.
he / she	Mae e / hi'n gallu mynd.	He / she can go.
we	Dyn ni'n gallu mynd.	We can go.
you, polite or plural	Dych chi'n gallu mynd.	You can go.
they	Maen nhw'n gallu mynd.	They can go.

A statement becomes a yes/no question through the form of bod: Dych chi'n gallu helpu? means “Can you help?” In a negative, put ddim after the subject: Dw i ddim yn gallu dod (“I cannot come”). Keep yn before gallu in the negative.

At this stage, use gallu for ability or practical possibility. Welsh also has shorter forms such as Alla i…?, as well as regional alternatives built with medru, but these are best treated as an extension of the core pattern; the related article listed below covers the contrast in more detail.

Obligation with rhaid

Rhaid means “necessity” or “it is necessary.” The person who must act is introduced by i (“to/for”), so the Welsh structure is closer to “it is necessary for me to go” than to the English one-word modal must.

Both Rhaid i fi fynd and Mae rhaid i fi fynd occur. The version without mae is compact and widely used; mae rhaid is also common, especially in speech. You will also encounter i mi in place of i fi, particularly in more neutral or formal varieties.

Person who must act	Common pattern	Meaning
me	rhaid i fi / i mi	I must
you, familiar singular	rhaid i ti	you must
him	rhaid iddo fe/fo	he must
her	rhaid iddi hi	she must
us	rhaid i ni	we must
you, polite or plural	rhaid i chi	you must
them	rhaid iddyn nhw	they must

The following verb-noun is normally soft-mutated (its first consonant changes in a regular grammatical environment):

• mynd → fynd: Rhaid i ni fynd. — We must go.
• dod → ddod: Rhaid iddi hi ddod. — She must come.
• gwneud → wneud: Rhaid i ti wneud hyn. — You must do this.
• prynu → brynu: Rhaid iddo fe brynu tocyn. — He must buy a ticket.

Not every initial letter visibly changes, so Rhaid i chi aros keeps aros, and Rhaid iddyn nhw weithio keeps gweithio because initial gw- loses only its g under soft mutation: gweithio → weithio.

For a question, Oes rhaid…? is a very useful pattern: Oes rhaid i fi dalu nawr? (“Do I have to pay now?”). For “do not have to,” use does dim rhaid: Does dim rhaid i chi ddod (“You do not have to come”). This means there is no necessity; it does not mean that coming is forbidden.

Obligation with gorfod

Gorfod means “to have to” or “to be obliged to.” Grammatically it behaves like gallu in the long present-tense pattern:

subject + form of bod + yn gorfod + verb-noun

• Dw i'n gorfod gweithio. — I have to work.
• Mae hi'n gorfod aros. — She has to wait.
• Ydy e'n gorfod talu? — Does he have to pay?
• Dyn ni ddim yn gorfod gyrru. — We do not have to drive.

Unlike the verb after rhaid i + person, the verb-noun after gorfod is not changed merely because it follows gorfod: gorfod mynd, gorfod dod, gorfod prynu.

For many everyday statements, rhaid i mi fynd and dw i'n gorfod mynd communicate nearly the same message. Rhaid presents the action as necessary; gorfod packages the obligation as something the subject has to do and can sometimes make an outside pressure feel more prominent. Context and regional preference often matter more than a sharp difference in translation.

Desire with eisiau and moyn

Use eisiau for wanting either a thing or an action:

• Dw i eisiau coffi. — I want coffee.
• Dw i eisiau mynd adref. — I want to go home.

With an action, place the second verb-noun directly after eisiau. Do not add a Welsh equivalent of English to: eisiau mynd, not eisiau i mynd. In the ordinary present construction, do not insert yn before eisiau either.

The same sentence frame works with other subjects:

Statement	Question	Negative
Rwyt ti eisiau te.	Wyt ti eisiau te?	Dwyt ti ddim eisiau te.
Mae hi eisiau mynd.	Ydy hi eisiau mynd?	Dyw hi ddim eisiau mynd.
Maen nhw eisiau aros.	Ydyn nhw eisiau aros?	Dydyn nhw ddim eisiau aros.

Moyn is a normal colloquial southern alternative: Dw i moyn coffi or Dw i moyn mynd adre. In northern speech, isio is a common pronunciation and informal spelling of eisiau. For broad, neutral written Welsh, eisiau is the safest form to produce; learn moyn and isio for recognition as well.

Questions and negatives at a glance

Function	Ability	Obligation	Desire
question	Wyt ti'n gallu dod?	Oes rhaid i ti ddod? / Wyt ti'n gorfod dod?	Wyt ti eisiau dod?
negative	Dw i ddim yn gallu dod.	Does dim rhaid i fi ddod. / Dw i ddim yn gorfod dod.	Dw i ddim eisiau dod.

This table exposes the most important structural contrast: yn remains with gallu and gorfod, but not with eisiau. The rhaid construction has its own question and negative forms.

Examples in Context

Welsh	English	Note
Dw i'n gallu nofio.	I can swim.	Basic ability pattern.
Dych chi'n gallu helpu?	Can you help?	Chi can be polite singular or plural.
Mae Ceri'n gallu gweithio o gartref heddiw.	Ceri can work from home today.	A named subject is followed by yn gallu.
Dw i ddim yn gallu dod nos Wener.	I can't come on Friday evening.	Ddim makes the sentence negative.
Mae rhaid i fi fynd.	I must go.	Common spoken obligation pattern from the concept.
Rhaid i ni brynu tocynnau ymlaen llaw.	We must buy tickets in advance.	prynu → brynu after i ni.
Oes rhaid i chi dalu heddiw?	Do you have to pay today?	Question with oes rhaid.
Does dim rhaid i ti frysio.	You don't have to hurry.	No necessity; brysio → frysio.
Mae hi'n gorfod codi'n gynnar yfory.	She has to get up early tomorrow.	Personal construction with gorfod.
Ydyn nhw'n gorfod aros yma?	Do they have to wait here?	Plural question.
Dw i eisiau coffi.	I want coffee.	Eisiau followed by a noun.
Dw i eisiau dysgu Cymraeg.	I want to learn Welsh.	Eisiau followed directly by a verb-noun.
Wyt ti eisiau mynd am dro?	Do you want to go for a walk?	Everyday invitation.
Dyw hi ddim eisiau gyrru heno.	She doesn't want to drive tonight.	No yn before eisiau.
Dw i moyn paned, os gwelwch yn dda.	I want a cup of tea, please.	Colloquial southern moyn.

Common Mistakes

Adding yn before eisiau

• Wrong: Dw i'n eisiau coffi.
• Right: Dw i eisiau coffi.
• Why: The usual present-tense desire pattern is bod + eisiau without the linking particle yn. This is an exception worth memorising as a complete phrase.

Omitting yn before gallu or gorfod

• Wrong: Dw i gallu nofio.
• Right: Dw i'n gallu nofio.
• Why: In the long present construction, gallu and gorfod follow bod + yn.

Copying English “to” after want

• Wrong: Dw i eisiau i mynd adref.
• Right: Dw i eisiau mynd adref.
• Why: Welsh places the verb-noun directly after eisiau. English “want to go” is a three-part English pattern, not a word-for-word template for Welsh.

Forgetting mutation after rhaid i + person

• Wrong: Rhaid i fi mynd nawr.
• Right: Rhaid i fi fynd nawr.
• Why: In this construction the following verb-noun normally undergoes soft mutation. Learn frequent chunks such as i fi fynd, i ti wneud, and i ni brynu.

Confusing “must not” with “do not have to”

• Wrong meaning: Does dim rhaid i ti fynd used for “You must not go.”
• Right: Does dim rhaid i ti fynd means “You do not have to go.” For prohibition, use a pattern such as Rhaid i ti beidio â mynd (“You must not go”).
• Why: Removing an obligation is different from forbidding an action, even though English learners sometimes treat mustn’t as a simple negative of must.

Adding a second subject to gorfod

• Wrong: Dw i'n gorfod i fi weithio.
• Right: Dw i'n gorfod gweithio.
• Why: With gorfod, the subject is already supplied by dw i. The i fi pattern belongs with rhaid: Rhaid i fi weithio.

Usage Notes

Welsh varies considerably by region, and modal expressions make that variation easy to hear. Eisiau is broadly useful in standard writing, isio is strongly associated with everyday northern speech, and moyn is especially common in the south. They are not simply “correct” and “incorrect” versions. A beginner can produce eisiau consistently while learning to recognise the others.

Pronouns also vary. You may hear i fi and i mi, iddo fe in much of the south, and iddo fo in much of the north. More formal writing often contracts i mi to imi, as in Rhaid imi fynd. Do not feel that you must mix every regional option. A consistent model based on your course, teacher, or local community is usually easier to learn and sounds more natural.

For requests, ability and permission are not always the same. Wyt ti'n gallu agor y ffenestr? literally asks whether someone can open the window, but in context it can function as a request, just like English “Can you open the window?” To ask permission for yourself, Welsh very commonly uses Ga i…?: Ga i fynd nawr? (“May I go now?”). That pattern belongs to the more focused topic of can, cannot, and permission.

Beyond the Basics: Advanced Use

You do not need to master these points at A1, but they explain forms you will meet later.

Welsh can conjugate some of these verbs directly instead of always using bod. For gallu, forms such as galla i (“I can”) occur, while questions and negatives often show initial mutation: Alla i ddod? (“Can I come?”), Allwch chi helpu? (“Can you help?”), and Alla i ddim dod (“I cannot come”). Northern Welsh frequently uses forms of medru, including Fedra i ddim…. These shorter forms differ by tense, person, and region, so the dependable beginner strategy remains dw i'n gallu….

The expression peidio â + verb-noun means “not to…” and is useful when obligation applies to avoiding an action: Rhaid i chi beidio â defnyddio'ch ffôn yma (“You must not use your phone here”). The word after â may show aspirate mutation where possible. This is a more precise way to express prohibition than does dim rhaid, which only removes necessity.

Eisiau can sometimes be translated as “need” rather than “want,” depending on the object and situation. Mae'r car eisiau ei olchi can convey that the car needs washing, though speakers also have other ways to express need. In formal or carefully written Welsh, you may encounter dymuno (“to wish”) where everyday speech would use eisiau, and polite wishes are often softened with conditional forms such as hoffwn i (“I would like”). These choices concern register and politeness rather than the basic A1 frame.

Finally, past and future obligation require tense changes elsewhere in the construction: forms of bod change with gorfod, while rhaid has its own wider set of patterns. Keep the present-tense frames stable first; later tense study will show how modal meaning combines with time.

Practice Tips

1. Build four sentence chains. Choose one action, such as mynd (“go”), and say Dw i'n gallu mynd, Rhaid i fi fynd, Dw i'n gorfod mynd, and Dw i eisiau mynd. Then repeat with aros, gweithio, and helpu.
2. Practise each statement as a question and a negative. Turn Dych chi'n gallu helpu into Dych chi'n gallu helpu? and Dych chi ddim yn gallu helpu; contrast that with Oes rhaid i chi helpu? and Does dim rhaid i chi helpu.
3. Learn mutations as chunks, not as an abstract list. Put rhaid i fi fynd, rhaid i ti wneud, rhaid i ni brynu, and rhaid iddi hi ddod on cards. The repeated frame will make the consonant changes easier to remember.

Related Concepts

• Prerequisite: Bod — Present Tense — supplies the present forms used with gallu, gorfod, and eisiau.
• Next step: Can and Cannot — develops gallu, methu, shorter question forms, and permission with Ga i…?.