［正］ We could not help laughing at once.

［正］

We could not help but laugh at once.

［析］ "couldn't help+动名词"表示禁不住做了某事。但could not help but与could not but后面要加不带to的不定式，意思都是不得不去做某事.如：You could not (help)

but respect him.

can be able to

can与be able to都可以用来表示能力，但can只有现在时与过去时，be able to则可用任何时态，如：He will be able to teach the child. 但要表示经过努力而达到的一次性动作则只能用be able to，如：He finally was able to jump over 210 meters. 或：The plane was able to fly over the mountain. 但要注意的是这两个词都没有进行时态，而be able to后面不接不定式的被动态。

can could

can与could都可以用在现在时的口语中，只是用could更为礼貌，语气更委婉。如：Could you tell us a story?

care

［误］

I don't care coffee.

［正］

I don't care for coffee.

［误］ Take care for your steps.

［正］

Take care of your steps.

［析］ care for是"对某物感兴趣"，而care of是"关心，要当心某事"，如：She didn't care for him. Take care of what you are doing.

［误］ I don't care where we will go if it doesn't rain.

［正］ I don't care where we go if it doesn't rain.

［析］ 在it doesn't matter, I don't care, I don't mind, 及in case引出的状语从句后面要用现在时表示将来。如：I've got a football in case we have time for a game.

change

［误］ I want to change my camera with that one.