The infinitive (-mek / -mak) and its uses
The dictionary form of every Turkish verb ends in -mek or -mak — the infinitive. gitmek = to go, yapmak = to do. But the infinitive is more than a citation form: it functions as a noun. Yüzmek güzel = swimming is nice. Gitmek istiyorum = I want to go. Çalışmak gerek = one needs to work. Today: how to use -mek/-mak as a noun, attach case endings to it, and combine it with istemek ('to want') and sevmek ('to love').
The infinitive as a bare noun
-mek/-mak alone names the activity, like English -ing or 'to-VERB'. Yüzmek = swimming / to swim. Konuşmak = speaking / talking. Okumak = reading. As subjects: Yüzmek güzel = swimming is nice. Erken kalkmak zor = getting up early is hard. Çok çalışmak yorucu = working a lot is tiring. The two forms (-mek vs -mak) follow front/back vowel harmony — that's the only difference.
Final -k drops before vowel suffixes
Crucial sound rule: when you attach a case ending that starts with a vowel, the final -k of the infinitive disappears. gitmek + -i (accusative) → gitme- + -yi (with buffer -y-) = gitmeyi. yüzmek + -i → yüzmeyi. okumak + -i → okumayı. This effectively turns the infinitive back into the -me/-ma verbal-noun stem. So when an ending follows, you'll see -me/-ma, not -mek/-mak: çalışmaya (to working), gitmeye (to going), yapmaktan (from doing — note: ablative -tan starts with a consonant, so the -k stays).
Use 1: with istemek (to want)
istemek + bare infinitive = 'to want to do X'. This is one of the most common Turkish patterns. Gitmek istiyorum = I want to go. Yemek istemiyor = he doesn't want to eat. Görmek istedim = I wanted to see. The infinitive stays in its -mek/-mak form (no case ending) right before istemek. istemek itself takes the personal endings and tense: istiyorum (I want), istiyorsun, istiyor, istemedim (I didn't want), etc.
Use 2: with sevmek (to love / to like) — uses accusative
sevmek takes the accusative form of the verbal noun, not the bare infinitive. The pattern is: stem + -me/-ma + -yi/-yı + sevmek. Yüzmek → Yüzmeyi seviyorum = I love swimming. Okumak → Okumayı severim = I love reading. Konuşmak → Konuşmayı sevmiyorum = I don't like talking. Watch the difference from istemek: with sevmek, drop the -k of the infinitive and add -yi/-yı. (Conceptually: sevmek wants a definite object, so it gets the accusative; istemek doesn't.)
Use 3: dative — for / to (an activity)
Drop -k and add dative -e/-a (with buffer -y- because the stem ends in a vowel) to mean 'to / for / about (an activity)'. Yüzmek → yüzmeye (to swim, dative). Used after verbs like gitmek (to go) when expressing purpose: Yüzmeye gidiyorum = I'm going swimming / I'm going to swim. Çalışmaya başladı = he started working / he started to work (the verb başlamak = 'to start' takes a dative). Konuşmaya hazır mısın? = are you ready to talk?
Use 4: with gerek and lazım (review of lesson 23)
Bare infinitive + gerek/lazım = impersonal 'one should / it's necessary to'. Çok su içmek lazım = one needs to drink a lot of water. Erken yatmak gerek = one should go to bed early. Bunu yapmak şart = doing this is essential. The bare infinitive (no possessive) keeps the meaning impersonal. To make it personal, switch to the -me + possessive pattern from lesson 23: içmem lazım (I need to drink). Both are correct; the bare infinitive is the cleaner 'general advice' shape.
Negation
Insert -me/-ma before the infinitive ending. Bare infinitive: gitmemek = not to go / not going. Sigara içmemek lazım = one shouldn't smoke. With istemek: gitmek istemiyorum = I don't want to go (negate istemek, not the infinitive — though gitmemek istiyorum is also possible and means 'I want NOT to go'). With sevmek: yüzmeyi sevmiyorum = I don't like swimming.
