Learn Turkish: Adam çok iyi anlıyor. - The man understands very well.

This happens because of a rule called "vowel narrowing," which is the focus of this lesson. When a verb root ends in a wide vowel like a or e (here, the root is anla-), and you add the present continuous suffix (-yor), that final vowel shrinks to a narrow vowel (ı, i, u, or ü). The a in anla- narrows to ı, giving us anlıyor.

Doesn't iyi mean "good"? Why is it translated as "well" here?

In English, we use "good" to describe things and "well" to describe actions. Turkish is simpler: most adjectives can also be used as adverbs without changing their form at all. So, iyi can mean both "good" and "well" depending on whether it describes a noun or an action.

How do we know it means "the man" and not just "a man"? There is no word for "the" here.

Turkish does not have a separate word for "the". When a noun is the subject of the sentence, we usually translate it with "the" in English unless there's a reason not to. If the speaker wanted to say "a man," they would usually add the word bir (one/a) and say Bir adam çok iyi anlıyor.

Why isn't there a personal suffix at the end of anlıyor to show who is understanding?