Learn Croatian: Kad je počela vikati, bio sam usred sastanka. - When she started to shout, I was in the middle of a meeting.

Kad means "when" and is used for a specific moment or a single event that interrupts something else. Here, her starting to shout is an action that happened at a point in time. If we wanted to say "while she was shouting" (two ongoing actions happening at the same time), we would use dok.

Why is the word for meeting sastanka instead of sastanak?

The preposition usred (in the middle of) always requires the noun that follows it to be in the genitive case. When sastanak changes to the genitive, it drops the final "a" from its base before adding the genitive "-a" ending. This is a very common spelling pattern in Croatian known as the "fleeting a".

Since there are no pronouns like "she" or "I" here, how do we know who is doing what?

We can tell by looking at the endings of the past tense verbs. Počela ends in "-la", which tells us a female is the one who started shouting. Bio ends in "-o", which tells us a male is speaking about himself being in the meeting. If a woman were speaking about herself, she would say bila sam.

Why does the second half of the sentence say bio sam instead of sam bio?

Short helper verbs like sam are called clitics, meaning they have strict rules and can never be the very first word in a sentence or a new clause. Because the comma creates a new clause, the main verb bio steps into the first position so sam can sit safely in the second position.