Learn Italian: Si frequentano e vanno spesso al cinema. - They are dating and go to the cinema often.

The verb frequentare means "to spend time with" or "to hang out with". By using the reciprocal pronoun si, it becomes frequentarsi, which means they spend time with each other. In Italian, this is the standard and most common way to say that two people are seeing each other or dating.

Why is the word loro (they) missing from the beginning of the sentence?

Italian usually drops subject pronouns because the verb endings already make it clear who is doing the action. Both frequentano and vanno are conjugated in the third-person plural form, which automatically implies "they". Adding loro here is not grammatically wrong, but it would sound unnecessary to a native speaker.

Why is spesso placed after the verb vanno instead of before it?

In Italian, adverbs of frequency like spesso (often) and sempre (always) generally go right after the verb they are modifying. So while English says "they often go", Italian phrasing works like "they go often" (vanno spesso).

Why do we use al before cinema instead of just a?