Learn Italian: Questa caramella sa di menta e aglio! - This candy tastes like mint and garlic!

While sapere usually means "to know a fact", when it is followed by the preposition di and a noun, it means "to taste of" or "to smell of" that noun. Here, sa di is used to introduce the flavors the candy has.

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

It relies entirely on context. Because the subject is a caramella (candy), we assume it is being eaten, so "tastes like" is the most logical translation. If you were just sniffing the wrapper, this exact same sentence would translate to "This candy smells like mint and garlic!"

Why don't we use the definite article for the flavors, like della menta e dell'aglio?

When describing a general flavor or scent with sapere di, you use the simple preposition di without the definite article. You would only use an combined preposition (like della or dell') if you were referring to a specific, previously mentioned ingredient, such as sa dell'aglio che hai comprato (it tastes like the garlic you bought).

Is it okay to write d'aglio with an apostrophe instead of di aglio?