Learn Hardcore Turkish: Perşembe günü öğleden sonra da uygunum. - I’m also available on Thursday afternoon.

It means also/too. It’s the enclitic particle da/de and is written as a separate word. It attaches to the phrase immediately to its left. Here it attaches to öğleden sonra, so the sense is “I’m also available in the afternoon.”

Why is it da and not de?

Vowel harmony: after a back vowel (a, ı, o, u) use da; after a front vowel (e, i, ö, ü) use de. The preceding vowel in sonra is a, so you choose da. Note: this particle is always written separately and never turns into ta/te (that alternation belongs to the locative suffix, not this particle).

Can I move da around? How does the meaning change?

Yes—its placement shows what is being added/compared.

Perşembe günü öğleden sonra da uygunum. Also in the afternoon (e.g., besides the morning) I’m available.
Perşembe günü de öğleden sonra uygunum. Also on Thursday (e.g., besides other days) I’m available in the afternoon.
Ben de Perşembe günü öğleden sonra uygunum. I, too, am available then (e.g., someone else was available).

Why is günü used after Perşembe? Do I need it?

Perşembe günü is a very common way to say “on Thursday.” Literally it’s “Thursday’s day,” an indefinite noun compound. You can drop it and say Perşembe öğleden sonra da uygunum with essentially the same meaning. Including günü often feels a bit more explicit or formal.

What exactly is the ending in günü—is it accusative?

Here it’s the 3rd-person possessive ending -(s)I forming the compound Perşembe günü (“the day [of] Thursday”), not accusative. Breakdown: gün + ü → günü.

Why not say Perşembe’de to mean “on Thursday”?

Turkish doesn’t use the locative for days of the week to mean “on.” You say Perşembe (günü). Also, Perşembe is the name of a town too, so Perşembe’de would be read as “in/at the town called Perşembe.”

What does öğleden sonra consist of?

öğle = noon
-den = from (ablative case)
sonra = after Together: öğleden sonra = after noon → “in the afternoon.” Similarly, öğleden önce = before noon, öğlen = at noon.

Is öğleden sonra a fixed adverb, or can it behave like a noun?

Both. As a time adverb it’s just öğleden sonra. To talk about “the afternoon” as a noun phrase, you can say öğleden sonrası (“the afternoon [part]”) and even add case: öğleden sonrasında (“in the afternoon”). In everyday scheduling, the simple adverbial form is most common.

How is uygunum formed—where is “am”?

Turkish doesn’t use a standalone present-tense “to be.” You add a personal ending to the predicate: uygun + -um (1st person singular) → uygunum = “I am suitable/available.” Vowel harmony picks -um because the last vowel in uygun is u.

Is uygunum the most natural way to say “I’m available”?

It’s fine (literally “I’m suitable/convenient”), but many speakers prefer müsaitim in scheduling: Perşembe günü öğleden sonra da müsaitim.

Do I need to say ben?

No. The ending -um already marks “I.” Add Ben for emphasis or contrast: Ben Perşembe günü öğleden sonra da uygunum.

Is there a difference between Perşembe günü and just Perşembe?

Not really in meaning here. Perşembe günü can feel a bit more natural or explicit; Perşembe alone is perfectly normal in speech: Perşembe öğleden sonra da uygunum.

How do I negate this with “also”?

Use değil with the correct personal ending, and keep da where you need “also”:

Perşembe günü öğleden sonra da müsait değilim. = I’m not available on Thursday afternoon either.

How do capitalization and apostrophes work with day names?

Days are normally lowercase in Turkish, but the first word of a sentence is capitalized—hence Perşembe here. When adding suffixes to day names, you do not use an apostrophe: perşembeye, perşembeden, perşembeyi. Example: Bu perşembeye kadar (“by this Thursday”).

How can I say “this/next/last Thursday afternoon”?

Bu perşembe öğleden sonra
Gelecek/Önümüzdeki perşembe öğleden sonra
Geçen perşembe öğleden sonra You can still add da: Bu perşembe öğleden sonra da uygunum.