Learn Italian: Questo caffè sa di cannella ed è disgustoso! - This coffee tastes like cinnamon and is disgusting!

While sapere primarily means "to know" (a fact), it has a secondary use related to the senses. When combined with the preposition di, sapere di means "to taste of" or "to smell of". It is the standard way to describe the specific flavor or scent of something.

Since sapere di can mean both "to smell like" and "to taste like", how do we know which one it is in this sentence?

It is entirely based on context! Because the subject is caffè (a food/drink), "tastes like" is the most natural assumption. However, without further context, "this coffee smells like cinnamon" would also be a perfectly valid translation.

Can I use the word come instead of di to say it tastes "like" cinnamon?

No, this is a classic trap for English speakers. We say "tastes like" in English, but Italian requires the preposition di (literally "tastes of"). If you said sa come cannella, an Italian might confusedly interpret it as "it knows how cinnamon [does something]"!

Why is it ed è instead of just e è?