Learn Croatian: Ne idemo vani zbog jake zime. - We are not going outside because of the strong winter.

The preposition zbog (because of) always forces the following noun into the genitive case. The base noun is the feminine zima (winter), which becomes zime in the genitive. Because adjectives must agree with the nouns they describe, the feminine adjective jaka (strong) also takes the genitive singular ending -e, giving us jake zime.

Can I use zato što (because) instead of zbog in this sentence?

Not exactly like this! Zbog is a preposition meaning 'because of' and is followed by a noun phrase (like jake zime). Zato što means 'because' and requires a full mini-sentence with a verb. You could say: Ne idemo vani zato što je zima jaka (We aren't going outside because the winter is strong).

Is it normal to describe winter as 'strong' (jaka) in Croatian?

Yes! In English, we usually talk about a 'severe' winter or 'bitter' cold, but in Croatian, the adjective jak (strong) is the natural choice for intense weather. You will also hear people talk about jaka kiša (heavy rain) or jak vjetar (strong wind).

I learned that van is used for going outside, and vani is for being outside. Why does this sentence use vani with the verb idemo (we go)?