Learn Turkish: Hastayken çaydan başka hiçbir şey içmiyordum. - While I was sick, I was drinking nothing except for tea.

The word başka means 'other' or 'different'. When you pair it with a noun in the ablative case (-DAn, meaning 'from'), the phrase -DAn başka translates to 'other than', 'except', or 'besides'. So, çaydan başka literally means 'other than tea'.

How do you get 'while I was sick' from just the single word hastayken?

The suffix -ken means 'while'. It can attach directly to adjectives or nouns to mean 'while being [adjective/noun]'. Because hasta ends in a vowel, we add the buffer letter y before -ken, making it hastayken. Note that -ken doesn't change based on vowel harmony, and the subject ('I' in this case) is understood from the main verb içmiyordum.

Hiçbir şey means 'nothing'. Why is the verb içmiyordum also negative? Isn't that a double negative?

Yes, it is! Unlike standard English, Turkish requires a negative verb when you use negative words like hiçbir şey (nothing), hiç kimse (nobody), or hiçbir zaman (never). You are literally saying 'I wasn't drinking nothing'.

Why use the past continuous içmiyordum instead of the simple past içmedim?