Learn Hardcore Turkish: Bugün bayağı yorgunum, yine de yürüyüşe çıkacağım. - I’m quite tired today, yet I’ll still go for a walk.

It’s the 1st‑person singular “to be” ending attached to an adjective/noun. Turkish usually doesn’t use a separate verb “to be” in the present; instead it adds personal endings.

yorgun = tired
yorgun-um = I am tired Vowel harmony picks the right vowel for the ending: -(y)im/ım/um/üm. Because the last vowel in yorgun is back/rounded (u), you get -um. Examples:
mutlu-yum (I am happy)
hasta-yım (I am sick)
hazır-ım (I am ready)
yorgun-sun (you are tired)
yorgun (he/she is tired; no ending in 3rd person)

Can I drop that ending and just say “Bugün bayağı yorgun”?

In standard speech/writing you shouldn’t. Predicative adjectives in Turkish normally need the personal ending: Bugün bayağı yorgun-um. Omitting it is only seen in very telegraphic styles (headlines, notes), and sounds incomplete in normal sentences.

How strong is bayağı? How does it compare to çok, oldukça, epey, gayet?

Roughly, from weaker to stronger: biraz < epey/epeyce ≈ oldukça ≈ bayağı/gayet < çok < aşırı. In many contexts bayağı means “pretty/quite,” a bit softer than çok (“very”). Note: as an adjective before a noun, bayağı can also mean “vulgar/low-brow/ordinary” (e.g., bayağı bir film), but here it’s an adverb meaning “quite.”

Is the spelling bayağı important? I often see baya.

Standard spelling is bayağı (with ğ and ı). The ğ lengthens/softens the preceding vowel; many people pronounce it like “bayaa” and casually write baya. That spelling is common informally, but bayağı is the correct form.

What exactly does yine de mean? Is it the same as “but”?

Yine de means “nevertheless/even so/all the same.” It concedes the first clause and contrasts it with the second: “I’m quite tired today; nevertheless I’ll go for a walk.” Ama is “but,” a coordinating conjunction. You can use both: …; ama yine de … for extra contrast. Without de, yine mostly means “again.”

Why is it yine de, not yine da or a single word like yinede?

It’s two words: yine de (never glued).
This de is the separate clitic meaning “also/too,” which follows vowel harmony (de/da) but never turns into te/ta. After yine (front vowel e), it’s de.
Compare: ben de, sen de, onlar da.

Is the comma before yine de necessary?

Recommended, yes. You can also make it two sentences: Bugün bayağı yorgunum. Yine de yürüyüşe çıkacağım. A semicolon works too. The comma marks the concessive contrast.

Why is it yürüyüşe with -e? What case is that?

It’s the dative case (-e/-a), roughly “to/for.” Yürüyüş (“walk, walking” as a noun) + -e = “for a walk” or “to a walk.” The last vowel in yürüyüş is front (ü), so you use -e by vowel harmony: yürüyüş-e.

But doesn’t çıkmak take the ablative (‑den) with places? Why dative here?

Both occur with different meanings:

Ablative (‑den): leaving a location. Ev-den çıkacağım = I’ll leave the house.
Dative (‑e): “going out for (an activity).” Common collocations:
- yürüyüş-e çıkmak (go out for a walk)
- alışveriş-e çıkmak (go out shopping)
- yemeğ-e çıkmak (go out to eat) So the dative marks the purpose/activity here.

How is çıkacağım formed?

Verb stem: çık- (to go out)
Future: -AcAK → çıkacak (A/E harmonizes: back vowel → -acak)
1sg ending: -(y)Im → -ım
Phonology: the k before a vowel softens to ğ → çıkacağım
Pronunciation tip: ğ lengthens/softens the preceding vowel; many say it like “çıka-caa-m.” Colloquially you may hear “çıkıcam,” but that’s nonstandard writing.

Could I say the present continuous instead: yürüyüşe çıkıyorum?

Yes. Turkish often uses the present continuous for near-future plans: (Yine de) yürüyüşe çıkıyorum ≈ “I’m going for a walk (still).” The future çıkacağım sounds like a decision/plan, promise, or something slightly more distant.

Can I move yine de or bugün around?

Yes, with slight changes in emphasis:

Yine de yürüyüşe çıkacağım (default; concessive sets up the clause).
Yürüyüşe yine de çıkacağım (focuses the “still” on the going-out part).
Bugün is flexible: Bugün bayağı yorgunum (neutral), Bayağı yorgunum bugün (emphasizes “today”).

Do I need to say Ben?

No. The personal ending already encodes the subject: (Ben) yorgunum, (Ben) çıkacağım. Use Ben only for emphasis/contrast: Ben yine de çıkacağım (“I, for my part, will still go”).

Could I say yürüyüş yapacağım or yürüyüşe gideceğim instead of yürüyüşe çıkacağım?

Yürüyüş yapacağım is fine and means “I will (do) a walk.” It emphasizes the activity.
Yürüyüşe çıkacağım is the most idiomatic for “go out for a walk.”
Yürüyüşe gideceğim is understandable but less idiomatic; speakers prefer … çıkmak for this purpose.

Is there a difference between yine de and hâlâ?

Yes:

yine de = “nevertheless/even so,” introducing a contrast with what precedes.
hâlâ = “still (continuing up to now).”
Here you want the concessive meaning, so yine de is correct.