Learn Turkish: Evde ayakkabı giymiyoruz. - We are not wearing shoes in the house.

The verb root is giy (wear). Normally, the negative suffix is -me. However, the -yor suffix changes the e or a right before it into a narrow vowel (i, ı, u, or ü). Following vowel harmony rules, -me changes to -mi, giving us giymiyoruz (we are not wearing).

Why is ayakkabı singular here if the English translation says "shoes"?

In Turkish, when you talk about a general, non-specific category of things, you usually use the singular form. Since the sentence is about wearing shoes in general rather than specific items, ayakkabı stays singular.

Why doesn't ayakkabı have an accusative object suffix?

Turkish only uses the accusative suffix for specific direct objects (like when saying "the shoes"). Because this sentence is about wearing shoes in general, ayakkabı is a non-specific object. Non-specific objects don't take a suffix and are usually placed right next to the verb.

What does the -de suffix in evde do?

This is the locative suffix, which means "in", "on", or "at". Added to ev (house), it becomes evde, meaning "in the house" or "at home".