English has one infinitive — "to do". Finnish has five, and beginners fear that for no reason: in real speech you constantly use just two — the first (the dictionary form) and the third (the -ma- forms). Let's take them in order and see where each belongs.
In short: the 1st infinitive is the dictionary form in -a/-da (puhua) and follows modal verbs. The 3rd infinitive (-massa, -maan, -malla, -matta) means "doing something, going to do, by doing". The other three are rarer.
1st infinitive — the dictionary form
This is the form you find in a dictionary: the ending -a / -ä or -da / -dä (puhua — to speak, tehdä — to do). It follows modal and many other verbs:
| Finnish | English |
|---|---|
| Haluan oppia suomea. | I want to learn Finnish. |
| Osaan uida. | I can swim. |
| Minun täytyy mennä. | I have to go. |
There is also a special "in order to" form: 1st infinitive + -kse- + a possessive suffix: Menin kauppaan ostaakseni maitoa (I went to the shop to buy milk).
3rd infinitive — the most useful one
The stem -ma- / -mä- plus a case ending. This is what gives you "going to do", "busy doing", "by doing":
| Form | Meaning | Example |
|---|---|---|
| -massa / -mässä | in the middle of (where) | Olen syömässä. — I'm eating (out). |
| -masta / -mästä | from (having done) | Tulen syömästä. — I'm coming from eating. |
| -maan / -mään | to (start doing) | Menen syömään. — I'm going to eat. |
| -malla / -mällä | by (means) | Opit puhumalla. — You learn by speaking. |
| -matta / -mättä | without doing | Lähti sanomatta mitään. — He left without saying anything. |
Remember the pair menen syömään (going to eat — to) and tulen syömästä (coming from eating — from): the direction is shown by the 3rd-infinitive ending, exactly like the local cases.
2nd infinitive — "while / by doing"
The stem -e-: the -essa form means "while", the -en form means "doing" (manner).
| Form | Example |
|---|---|
| -essa/-essä (while) | Puhuessani suomea jännitän. — While speaking Finnish, I get nervous. |
| -en (doing) | Hän tuli hymyillen. — He came in smiling. |
4th and 5th — briefly
- 4th infinitive — a verbal noun in -minen: uiminen (swimming), lukeminen (reading). It's really a noun and declines like one.
- 5th infinitive — -maisillaan, "about to": Olin kaatumaisillani (I was about to fall). Rare, but neat.
How not to mix them up
Don't try to memorise all five at once. Start with the 1st (after modals) and three forms of the 3rd (-massa / -maan / -malla): that covers 90% of sentences. The rest comes with reading. It helps to review the verb types alongside — they decide how the stem is formed.
Infinitives are the joints between verbs, where natural speech lives. The fastest way to make them automatic is with a teacher: at Hei Study we drill grammar on real phrases, not tables for their own sake — see how long Finnish really takes and start from there.