Learn Croatian: Čovjek je velik, a vi ste mali. - The man is big, and you are small.

vi means you when talking to multiple people, or formally to one person. Because it is a plural pronoun, it must be paired with the matching plural verb for are, which is ste.

Why does this sentence use a instead of i for the word and?

While i means and for linking similar things together, a is used to show a contrast (often translated as and, but, or while). Since the sentence contrasts a big man with small people, a is the correct choice here.

Why is the word for small mali?

Adjectives must match the word they describe. Because vi (you) is plural here, the adjective takes the plural ending -i (assuming a group of males or a mixed group), making it mali.

Why does velik end in a consonant, but mali ends in a vowel?

velik describes čovjek (man), which is a single male. Masculine singular adjectives usually end in a consonant. mali describes the plural vi, and masculine plural adjectives end in the vowel -i.