How often: thường, luôn, thỉnh thoảng before the verb

Words for how often go after the person and before the verb, much as in English "I usually drink coffee": Tôi thường uống cà phê.

From most to least often, the main ones are luôn or luôn luôn (always), thường (usually), thỉnh thoảng or đôi khi (sometimes), ít khi (rarely) and không bao giờ (never). Hay, the everyday spoken word for "often", sits in the same place: Tôi hay đi bộ. In everyday speech, "always" is also very often lúc nào cũng before the verb: Ba tôi lúc nào cũng dậy sớm. My dad always gets up early.

The sometimes-words are freer. Thỉnh thoảng, đôi khi and nhiều khi (quite often) can also open the sentence: Thỉnh thoảng em nấu cơm ở nhà. Sometimes I cook at home.

Thường xuyên means "regularly, frequently". It sounds a little more formal, and you'll often see it in writing: thường xuyên tập thể dục, exercise regularly. Hiếm khi means the same as ít khi and is also a little more formal.

After a verb, luôn means something else: "right away" (Làm luôn đi! Do it now!), and also "too, as well" or "for good" (Ăn luôn cái này. Eat this one too. Nó đi luôn rồi. He's gone for good.)