English has one infinitive: to do. Finnish has five, and calling them all "infinitives" hides what they really are — non-finite forms of the verb that behave like nouns and take case endings. A single Finnish verb can appear as tehdä, tehdäkseni, tehdessä, tehden, tekemässä, tekeminen, or tekemäisilläni, and each of those is doing a job that English splits across "to do," "in order to do," "while doing," "doing," and "the act of doing." This page is the map; each infinitive has its own detailed page linked below.
The single most important thing to grasp: these are not tenses. They carry no person and no time of their own. Time and subject come from the main clause. What changes between them is the case ending bolted onto the verb stem — and that ending is what carries the meaning.
The five infinitives at a glance
| # | Marker | Example (from puhua "to speak") | Job |
|---|---|---|---|
| 1st | -a / -da / -la… | puhua | the dictionary form; bare complement after modal verbs |
| 1st (long) | -akse- + poss. | puhuakseni | purpose: "in order to speak" |
| 2nd (inessive) | -essa / -essä | puhuessani | simultaneity: "while I speak/spoke" |
| 2nd (instructive) | -en | puhuen | manner: "speaking / by speaking" |
| 3rd | -ma- / -mä- + case | puhumassa, puhumaan, puhumalla… | location, goal, means, absence of an activity |
| 4th | -minen | puhuminen | a true verbal noun: "speaking, the act of speaking" |
| 5th | -maisilla- + poss. | puhumaisillaan | "on the verge of speaking" |
Modern reference grammars often rename the first three by their marker letter — the A-infinitive (1st), the E-infinitive (2nd), and the MA-infinitive (3rd) — while treating -minen as a noun-forming suffix. The traditional five-way numbering is still the standard scaffolding for learners, so we keep it, but do not expect the "4th" and "5th" to feel like the first three: they are really a noun and a fixed idiom.
What each one does
The first infinitive is the everyday one — the form your dictionary lists. It follows modal-like verbs (haluan puhua "I want to speak," osaan uida "I can swim," täytyy mennä "must go") and can stand as a subject.
Haluan oppia soittamaan kitaraa.
I want to learn to play the guitar.
The long first infinitive adds the translative -kse- plus a possessive suffix for purpose — "in order to." It is a flagship written-Finnish construction.
Opiskelen ahkerasti puhuakseni sujuvaa suomea.
I study hard in order to speak fluent Finnish.
The second infinitive comes in two cases. The inessive -essa/-essä means "while X-ing" (simultaneous action); the instructive -en describes the manner of an action.
Kävellessäni töihin kuuntelen aina podcasteja.
While walking to work I always listen to podcasts.
Hän poistui huoneesta hymyillen.
She left the room smiling.
The third infinitive is the -ma-/-mä- form that takes five different cases, each answering a spatial-style question: olen syömässä "I'm out eating" (inessive), tulen syömästä "I'm coming from eating" (elative), menen syömään "I'm going to eat" (illative), syömällä "by eating" (adessive), syömättä "without eating" (abessive).
Kieltä oppii parhaiten puhumalla.
You learn a language best by speaking.
The fourth infinitive -minen is a genuine noun — it declines like any -nen word and can be a subject or object.
Uiminen on hyvää liikuntaa.
Swimming is good exercise.
The fifth infinitive -maisilla-/-mäisillä- plus a possessive suffix means "on the point of, about to." It is rare and literary-flavoured, but worth recognising.
Olin jo nukahtamaisillani, kun puhelin soi.
I was already about to fall asleep when the phone rang.
The core error: picking the wrong Finnish infinitive for English "to do"
Because English wraps everything in one word — "to" — learners reach for the first infinitive everywhere. But Finnish chooses the infinitive by what governs it. The clash you will make first is between the plain first infinitive and the third-infinitive illative -maan/-mään:
- After modal-like verbs (haluta, voida, osata, aikoa, täytyä) → first infinitive (-a): haluan mennä "I want to go."
- After motion and beginning verbs (mennä, tulla, lähteä, oppia, ryhtyä) → third infinitive illative (-maan): menen ostamaan "I go to buy."
Haluan mennä kotiin.
I want to go home. (modal haluta → first infinitive)
Lähden ostamaan ruokaa.
I'm off to buy some food. (motion verb → third infinitive illative)
Vowel harmony runs through all of them
Every one of these markers has a back and a front variant, chosen by the stem's vowels: puhua → puhumaan, puhuessa, puhuen but syödä → syömään, syödessä, syöden; tehdä → tekemässä, tehdessä. The one marker that never harmonises is the second-infinitive instructive -en, which stays -en even on a front-vowel verb: syödä → syöden, never *syödän. Watch this on every form you build.
Common Mistakes
❌ Haluan menemään kotiin.
Incorrect — haluta takes the first infinitive, not -maan: haluan mennä.
✅ Haluan mennä kotiin.
I want to go home.
❌ Menen ostaa maitoa.
Incorrect — a motion verb takes the third infinitive illative, not the bare first infinitive: menen ostamaan.
✅ Menen ostamaan maitoa.
I'm going to buy milk.
❌ Syöessäni katson uutisia.
Incorrect — the second infinitive of syödä keeps its stem consonant: syödessäni.
✅ Syödessäni katson uutisia.
While I eat, I watch the news.
❌ Hän lähti juostän.
Incorrect — the instructive -en never harmonises to -än: juosten.
✅ Hän lähti juosten.
He ran off / He left at a run.
Key Takeaways
- Finnish has five infinitives; they are non-finite noun-like verb forms, not tenses, and they take case endings.
- The first is the dictionary form (and its long -kse- variant means "in order to"); the second appears in the inessive (-essa, "while") and instructive (-en, "manner"); the third takes five cases in -ma-; the fourth (-minen) is a verbal noun; the fifth (-maisilla-) means "about to."
- English "to do" maps onto different Finnish infinitives depending on the governing verb: modal verbs take -a, motion verbs take -maan.
- Every marker harmonises to the stem — except the instructive -en, which is always -en.
Now practice Finnish
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Start learning Finnish→Related Topics
- The First Infinitive: the Dictionary FormA1 — The first infinitive is the form dictionaries list (puhua, syödä, tulla). It follows modal-like verbs and can be a subject — but it is not the verb's stem.
- The Third Infinitive -ma-: An OverviewB1 — The -ma-/-mä- infinitive names an action as a place you are in, go into, or come from — the base for six case forms like syömässä, syömään and syömästä.
- The Fourth Infinitive -minenB1 — The -minen verbal noun turns any verb into a full noun (uiminen 'swimming') that declines like a -nen word: tekemisen, tekemistä, tekemiseen.
- Which Infinitive? A GuideC1 — A decision guide to Finnish verb complementation: when to use the first infinitive, the -maan third infinitive, -minen, an että-clause, or the referative.
- How Finnish Verbs WorkA1 — A map of the Finnish verb: six personal endings and pro-drop, six verb types that fix the stem, the tenses and moods, the separate negative verb, and non-finite forms.