Learn Turkish: Kapı kapalıydı, bu yüzden pencereden girebildik. - The door was closed, therefore we managed to enter through the window.

We start with the verb root gir- (to enter). We add the ability suffix -ebil to get girebil- (able to enter). Then we add the past tense suffix -di (was able to) and the personal ending -k for "we". This makes girebildik (we were able to enter / managed to enter).

Why does pencere (window) take the -den suffix if it means "through"? Doesn't -den mean "from"?

Yes, the suffix -den / -dan usually translates to "from". However, when talking about passing through an opening like a door or a window, Turkish uses this same suffix. So pencereden is the natural way to say "through the window".

Why is there a -y- in kapalıydı?

The adjective for "closed" is kapalı, which ends in a vowel. To say "it was closed", we add the past tense suffix -dı. Whenever we attach this past tense ending directly to a noun or adjective ending in a vowel, we must use the buffer letter -y- to link them together.

What is the literal meaning of bu yüzden?