Learn Turkish: Depremden beri sokakta kalıyorlar. - They have been staying on the street since the earthquake.

The postposition beri (since) always requires the word before it to take the ablative case (-den or -dan, meaning 'from'). You can think of depremden beri as literally meaning 'from the earthquake since'.

The English translation says 'have been staying', but isn't kalıyorlar just present continuous ('are staying')?

Yes! In English, we use perfect tenses for something that started in the past and continues now. In Turkish, if the action is still happening right now, you just use the present continuous tense (-ıyor). Because they are still on the street, Turkish expresses this as 'Since the earthquake, they are staying on the street.'

Why is the word for 'on the street' written as sokakta instead of sokakda?

This is because of consonant harmony. The word sokak ends with k, which is a voiceless consonant. This forces the locative ending -da (in/on/at) to harden into -ta so it flows more naturally when speaking.

Could we use yaşıyorlar (they are living) instead of kalıyorlar in this sentence?