The conditional (-se / -sa, 'if')
Turkish builds 'if' inside the verb itself, as a suffix — there's no separate 'if' word for ordinary conditionals (though eğer can introduce the clause optionally). The marker is -se / -sa by two-way harmony, attached after a tense marker or directly to the stem, then followed by a personal ending. Gelirsen = if you come. Yağmur yağarsa = if it rains. Param olsa = if I had money. Today: how to layer -se/-sa onto the tenses you already know, and what each combination means.
How to form it — tense + -se/-sa + person
The simplest 'real' conditional ('if X happens') sits on top of the aorist: stem + aorist marker + -se/-sa + person ending. gelmek → gel- + -ir- + -se- + -n = gelirsen (if you come). yapmak → yap- + -ar- + -sa- + -n = yaparsan (if you do). The personal endings here are the -di-style endings from lesson 18: -m, -n, nothing, -k, -niz, -ler. So: gelirsem (if I come), gelirse (if he comes), gelirsek (if we come), gelirseniz (if you-pl come), gelirlerse / gelirseler (if they come).
Conditional + future = real predictions
Turkish often combines conditional clause + future main clause, just like English 'if X happens, Y will happen'. Yağmur yağarsa, evde kalacağım = if it rains, I'll stay at home. Erken gelirsen, birlikte yemek yeriz = if you come early, we'll eat together. Çalışırsan başarılı olursun = if you work, you'll be successful. The conditional is in the aorist (yağarsa, gelirsen), the result clause uses the future or aorist. eğer is optional — you can add it for emphasis: Eğer yağmur yağarsa…
Conditional on the verb 'to be' — -se/-sa directly on a noun/adjective
To say 'if X is Y', you can attach -se/-sa directly to the predicate, with a buffer -y- if needed. Hasta- + -y- + -sa- + -n = hastaysan (if you are sick). Mutlu- + -y- + -sa- + nothing = mutluysa (if he is happy). Ev- + -de- + buffer -y- + -se- + -n = evdeysen (if you are at home). Same idea applies to the past: iyiydiyse style is rare; in spoken Turkish, iyiyse plus context handles it.
The hypothetical / contrary-to-fact: -se/-sa on the bare stem
When you want 'if I were…' or 'if I had…' — a hypothetical you don't expect to happen — drop the tense marker and attach -se/-sa directly to the verb stem. Param olsa, bir ev alırdım = if I had money, I'd buy a house. Vaktim olsa, gelirdim = if I had time, I'd come. Sen yerinde olsam… = if I were in your shoes… The result clause typically uses the aorist past (alırdım, gelirdim) — the 'would' tense, which Turkish builds as aorist + -di copula.
Common conditional connectives
eğer = 'if' as a clause-introducer (optional, emphatic). Eğer gelirsen, ben de gelirim = if you come, I'll come too. -se de = 'even if'. Yağmur yağsa da, gideceğim = even if it rains, I'll go. -sin diye = 'so that' (different construction, mentioned for contrast). eğer + future-conditional is very common in everyday speech: Eğer yarın görüşürsek… = if we see each other tomorrow…
Negation
Insert -me/-ma before the tense / before -se as appropriate. Real conditional negative: gelmezsen = if you don't come (negative aorist + -se + -n). Hypothetical negative: olmasaydı = if it weren't (so) — bare stem + -ma- + -sa- + past -y-dı. Common phrase: Gelmesen olmaz = it won't do if you don't come / you have to come (literally 'if you don't come, it won't be').
Quick reference
Gelirsen (real, present-future) = if you come. Gelirsen gelirim = if you come, I'll come. Gelseydin (counterfactual past) = if you had come. Gelsen (hypothetical present) = if you were to come / if you came. Yağmur yağarsa = if it rains (real). Yağmur yağsa = if it were to rain (hypothetical). The aorist + -se/-sa is your default 'if'; the bare stem + -se/-sa is the wishful / contrary-to-fact version.
