How you do it: adjective after the verb (nói giỏi, chạy nhanh)

English usually adds -ly to say how something is done: quickly, carefully. Vietnamese simply puts the plain adjective after the verb: nói nhanh (speak fast), lái xe cẩn thận (drive carefully), ngủ ngon (sleep well).

If the verb has an object, the object usually comes first and the adjective goes last: nói tiếng Việt giỏi (speak Vietnamese well), nấu ăn ngon (cook well, literally "cook tasty"). With a few common verbs you'll also hear the adjective first: nói giỏi tiếng Việt. Words like rất, lắm and quá sit next to the adjective as usual: nói rất giỏi, nói giỏi lắm, nói giỏi quá!

It's the same idea as describing a thing, where the description follows the noun: nhà lớn, a big house.

To ask how well, put có … không around the adjective: Em nói tiếng Việt có giỏi không? For "not well", put không, or chưa (not yet), before the adjective: Em nói chưa giỏi lắm is the modest answer to a compliment.

Two set phrases: Chúc ngủ ngon is "good night", and ăn ngon means eating well and enjoying your food.