Learn Croatian: Takav osmijeh je vrlo privlačan. - A smile like that is very attractive.

Takav is an adjective meaning "such a" or "that kind of." Because it describes the noun osmijeh (smile), it has to match its gender (masculine) and case (nominative). Tako is an adverb meaning "so" or "in that way," which is used to describe verbs or adjectives, not nouns.

Why does the English translation say "a smile like that" when takav is at the beginning?

In Croatian, takav literally means "such" or "of that kind." Since it acts as an adjective, it goes right before the noun it modifies (takav osmijeh = such a smile). English often prefers to put "like that" after the noun, but the Croatian word order stays strictly adjective-noun.

Why does the adjective privlačan end in -an instead of the typical masculine ending -ni?

Because it is the indefinite form of the adjective. In Croatian, when a masculine adjective comes after the verb "to be" (je) to describe the subject, you use the shorter indefinite form. So we use privlačan (is attractive) instead of privlačni (the attractive).

I often see the word smijeh. How is it different from osmijeh?

Osmijeh specifically means a "smile" (the silent facial expression), which fits here since a smile is visually attractive. Smijeh means "laughter" or "a laugh" (the audible action).