I saw him play/playing soccer at 4 o'clock yesterday

I saw him play/playing soccer at 4 o'clock yesterday 如 At 7 o"clock YESTERDAY evening i heard him _____ (唱歌） in t I saw him ____(play)the piano this time yesterday. we_____Paris at 4:00 o'clock yesterday. I saw them play football at this time yesterday. I saw him yesterday afternoon I _____ (do) my homework at five o’clock yesterday. I was dong my homework at nine o’clock yesterday I saw the children at play outside yesterday 和I saw the chil He __upstairs because I saw him playing football on the play I saw him ____football just now.是填play还是playing I like playing soccer中的playing为什么不是play