Learn Hardcore Turkish: Uyumadan önce sürgü çekmeyi unutma. - Don't forget to slide the latch before sleeping.

kilit/kilitlemek: lock/lock with a key
mandal/mandallamak: latch/clip with a catch or clasp There’s also the verb sürgülemek “to bolt,” which you might hear as Sürgülemeyi unutma , but sürgü çekmek is very common.

Because önce (before) requires its complement in the ablative case. With verbs, you make a verbal noun using -mA and then add ablative -DAn: uyu-ma-dan. So:

Before V: V-mA-dAn önce (Uyumadan önce) This is different from the dative -A (uyumaya), which would not work with önce.

Does -madan mean “without doing”? How does that square with “before sleeping”?

On its own, V-mA-dAn means “without doing V” (e.g., Kahvaltı yapmadan çıkma = Don’t leave without having breakfast). But when you add önce after it, the meaning becomes “before doing V.” So:

Uyumadan = without sleeping (by itself)
Uyumadan önce = before sleeping

Why not say Uyuduktan önce?

For “after doing,” Turkish uses a different pattern:

After V: V-DIk-tAn sonra (e.g., Uyuduktan sonra = after sleeping) “Before” pairs with -mA-dAn önce, not -DIk-tAn önce, so Uyuduktan önce is unidiomatic.

What exactly is sürgü?