Learn Croatian: Otac ga je jučer nazvao. - The father called him yesterday.

In Croatian, the past tense is made of two parts: a helper verb and a main action word. Here, the helper is je (the 'is' form of the verb 'to be') and the main action is the l-participle nazvao (called).

Why does the verb nazvao end in an 'o' if the lesson is about the 'l-participle'?

Even though it is called the l-participle, the masculine singular form usually ends in -o or -ao. This is because historically, an 'l' at the end of a word turned into an 'o'. If the subject were feminine, like a mother calling, you would see the 'l' return: nazvala.

Why are ga and je grouped together right after otac?

Both ga (him) and je (is) are clitics, which are short, unstressed words. Croatian has a strict rule that clitics must go in the second position of a sentence. Here, they immediately follow the first word, otac.

Why is the word order ga je and not je ga?

When multiple clitics stack up in the second position, they follow a strict order. The helper verb je is a special case: it almost always goes at the very end of any group of clitics, so the pronoun ga has to come first.