fast這個單詞，它是形容詞，是副詞，是動詞，是名詞。使用時，要注意他的詞性和含義。用法如下：
1.作形容詞 adj.
快的、牢固的、緊緊的、放蕩的
I will give you two munites for your fast reading.快速的
You are so fast.快速的
A big stone is fast in the ground.緊緊的
She plays with the fast men.放蕩的
2.作副詞 adv.
快速地、緊緊地、放蕩地
She drives the cool car fast.快速地
We must learn to read fast.快速地
You stuck it fast.緊緊地
The boy held the ball fast.緊緊地
That woman led a fast life.放蕩地
3.作動詞 vi.
節食、禁食、齋戒
You should fast before you leave the hospital.
He fasted for two days.
4.作名詞 n.
齋戒、禁食
The old man had some water during his fast.
Don't break your fast.
5.其他詞義，如不褪色的，fast color, 熟睡 fast asleep等。
對於fast這個單詞，能掌握以上這些含義，就掌握了它的基本用法。