Learn Turkish: Korkudan kasıldı ve boynu tutuldu. - He tensed up from fear and got a stiff neck.

In Turkish, the ablative case (-dan / -den) is often used to show the physical or emotional cause of an action. Here, korkudan translates to 'out of fear' or 'because of fear.' It acts as an adverb, explaining exactly why the physical reaction happened.

Is the verb kasıldı related to the noun kas (muscle)?

Yes, they share the same root! Kas means 'muscle,' and the verb kasmak means 'to tighten' or 'to strain.' By adding the passive/reflexive suffix -ıl, we get kasılmak, which means 'to tense up' or 'to contract.' In this context, it describes the involuntary tensing of the body.

Why is the word for neck written as boynu instead of boyunu?

The dictionary form of the word is boyun (neck). When we add a suffix starting with a vowel, like the third-person possessive -u to mean 'his neck', the narrow vowel in the second syllable drops out. This vowel omission is extremely common with two-syllable body parts (for example, burun becomes burnu and karın becomes karnı).

Does tutuldu literally mean 'was held' here?