we sat around and ＿＿(watch) the teacher ＿＿(show) us how to d

題目：

we sat around and ＿＿(watch) the teacher ＿＿(show) us how to do it.
我只知道watch sb do/doing.我想知道這兩者的區別是什麼?還有,and前面的動詞與and後面的動詞的形態一定要保持一致嗎?

解答：

Watch sb. do是說看到某種動作,而watch sb. doing是說看到做某事的過程. 這句話里用showing最恰當因爲"show(ing) us how to do it"是一個過程而不是某個動作.
用and是要動詞前後一致,除了前面用不定式的情況.例如這句話要填watched,但如果這句話被改爲"we were required (to sit) around and (watch)."就要用原型而不是"to watch".