非谓语动词do和doing两种是一样的吗？是不是要分场合用呢？

doing是某个点，do是全过程。比如说看见他在过马路和看见他过马路（全过程的，从开始过直到过去了。）

ex. I hear her singing我听见她在唱歌
I hear her sing我完整地听了她唱歌

而且我记得不是to do,是see sb do sth

通常感觉上，doing是状态，to do有种动作的感觉在里面，有目的性的。

我学的那会儿是这样，不知道五、六年过去了有没有变化，语言这东西于是俱进的~

DO has very many meanings.

You can see them here:

http://dictionary.cambridge.org/results.asp?searchword=do

do IndicativeIndicative PresentIndicative PastIndicative Present PerfectIndicative PluperfectIndicative FutureIndicative Future PerfectConditionalConditional PresentConditional PastSubjunctiveSubjunctive PresentSubjunctive PastSubjunctive Present PerfectSubjunctive PluperfectSubjunctive FutureSubjunctive Future PerfectImperativeImperative PresentParticipleParticiple PresentParticiple Past

Indicative:
Present:
I do
you do
he/she/it does