began to do和 began doing的具体含义不同，前者是开始打算要做某事，是指事情还未做，准备开始做；后者是指开始做某事，表示动作正在进行。begin后接动词不定式时多强调新情况的发生，动作是否继续下去则不考虑。接动名词时，对新动作本身注意较多，而且这动作还将持续一段时间。
You can't begin to imagine how much that saddens me.
你都无从想象这让我有多悲伤。
If relations between Hanoi and Washington begin to normalise, anything is possible.
如果河内和华盛顿之间的关系开始恢复正常，**事情都有可能。
You begin to ask yourself what kind of person perpetrated this crime.
你开始自问是什么样的人犯下这样的罪行。
Some analysts believe that the government soon will begin relaxing economic controls.
一些分析人士认为政府不久将开始放松经济管制。
When the aims of the partners begin to diverge, there'strouble.
当合作伙伴的目标开始出现分歧时，麻烦就产生了。