Learn Hardcore Turkish: Sağlıklı kalmak amacıyla her sabah parkta yürüyorum. - I walk in the park every morning for the purpose of staying healthy.

sağlıklı (adjective “healthy”) + kalmak (infinitive “to stay”) gives “to stay healthy.”
amaç (noun “aim, purpose”) + the instrumental suffix -yla (“with”) fuses into amacıyla, literally “with the purpose.”
Together sağlıklı kalmak amacıyla means “with the purpose of staying healthy,” i.e. “in order to stay healthy.”

Why is kalmak used here instead of olmak?

olmak means “to be” or “to become,” so sağlıklı olmak would be “to be/become healthy.”
kalmak means “to remain” or “stay,” so sağlıklı kalmak conveys “to stay healthy,” emphasizing maintaining one’s health rather than just attaining it.

What’s the difference between her sabah and sabahları for “every morning”?

her (“each, every”) must attach to a singular noun: her sabah = “every morning.”
sabahları is the plural + locative of sabah (“morning”) and means “in the mornings.”
Both express a habitual time frame, but her sabah is more precise (“each individual morning”), whereas sabahları is more general (“mornings, as a habit”).

What case is parkta, and what would change if it were parka or parkı?

parkta = park + locative -ta, indicating “in/at the park.”

parka (dative) would mean “to the park.”
parkı (accusative) would treat “the park” as a direct object (“the park” as something acted upon).
Here we need location, so the locative parkta is correct.

Why is yürüyorum in the present continuous rather than the simple present yürürüm?

Turkish often uses the present continuous (şimdiki zaman) for habitual actions too: Her sabah parkta yürüyorum can mean “I walk every morning.”
The simple present (geniş zaman) Her sabah parkta yürürüm is also correct but has a slightly more “general truth” feel. yürüyorum can sound a bit more vivid or like a current routine.

Why don’t we see ben in yürüyorum? Where’s “I”?

Turkish verbs carry person information in their endings. -um in yürüyorum already means “I.”
Adding ben (“I”) is possible for emphasis—Ben her sabah parkta yürüyorum—but is usually omitted as redundant.

Could I use sağlıklı kalmak için instead of sağlıklı kalmak amacıyla?

Yes. için means “for, in order to,” so sağlıklı kalmak için = “in order to stay healthy.”
–için is more colloquial and very common in spoken Turkish. amacıyla is a bit more formal or stylistically marked.

Is the word order Her sabah parkta yürüyorum fixed? Could I say Parkta her sabah yürüyorum?

Turkish is fairly flexible with adverbial phrases.

Her sabah parkta yürüyorum (time ⇒ place ⇒ verb) is neutral.
Parkta her sabah yürüyorum (place ⇒ time ⇒ verb) is also fine, though it slightly shifts the emphasis to “in the park.”
In both cases the core meaning remains “I walk every morning in the park.”

Why isn’t there an article before parkta, like “a park” or “the park”?

Turkish has no definite or indefinite articles.
parkta can mean “in a park” or “in the park” depending on context. Here it’s understood as “in the park” where you know which park or just “in a park” as a general routine.