Learn Hardcore Turkish: Yürürken oksijen ihtiyacımız yükselir ve kalp atış hızımız değişir. - While walking, our need for oxygen increases and our heart rate changes.

-ken attaches to the aorist stem of a verb to form an adverbial clause of time, meaning “while [verb]ing.”
Example:
• yürümek (to walk) → aorist stem yürür- → yürür + ken = yürürken (while walking)

Could you use yürüyorken instead of yürürken?

Yes. yürüyorken uses the present-continuous stem (yürüyor- + -ken) to emphasize an ongoing action:
• yürürken (aorist) = general “while walking”
• yürüyorken (continuous) = more vivid “while I’m walking”

Why doesn’t oksijen ihtiyacımız have a case suffix (like -e or -ı)?

In the clause oksijen ihtiyacımız yükselir, oksijen ihtiyacımız is the subject of yükselir (rises), and subjects in Turkish remain in the unmarked (nominative) form.

Why doesn’t oksijen have a genitive -in when it modifies ihtiyaç?

In Turkish noun-noun compounds, the first noun (oksijen) directly modifies the second (ihtiyaç) without an overt genitive. The possessive suffix (-ımız) goes on the head noun (ihtiyaç) → oksijen ihtiyacımız (“our oxygen need”).

Why is ihtiyaç marked with -ımız but not oksijen?

Possessive endings attach to the head noun of a phrase. Here, ihtiyaç is the head, so it takes -ımız (“our”), while oksijen remains unmarked.

Why are yükselir and değişir in the 3rd person singular when the sentence refers to “we”?

Turkish verbs agree with their grammatical subject—here the singular noun phrases oksijen ihtiyacımız and kalp atış hızımız—not with the logical actor biz. Hence the 3rd sg endings.

What does kalp atış hızımız literally mean, and how do these nouns combine?

• kalp = heart
• atış = beat
• hız = speed/rate
• -ımız = our
Literally “our heart-beat speed,” i.e. “our heart rate.” Turkish stacks modifiers before the head noun: kalp modifies atış, and kalp atış modifies hız.

Why don’t ihtiyacımız or kalp atış hızımız get pluralized with -lar/-ler?

Both ihtiyaç (“need”) and hız (“speed/rate”) are treated as uncountable or general concepts here, so they stay singular in Turkish.

Why are there no articles (like a or the) in this sentence?

Turkish has no articles. Definiteness or indefiniteness is inferred from context or expressed with case endings, so you simply use the noun without a separate “a” or “the.”

Why is there no comma before ve in … yükselir ve kalp atış hızımız değişir?

Turkish generally does not insert a comma before the coordinating conjunction ve in simple coordinate clauses. Commas are used sparingly and only for clarity in more complex sentences.

What is the difference between yükselmek and artmak, both often translated “to increase”?

• yükselmek = “to rise” (emphasizes a rise, often used for levels, rates, needs)
• artmak = “to increase” (more general, used for volume, quantity, etc.)
You could say oksijen ihtiyacımız artar instead of yükselir, but yükselmek highlights a rising trend.