语法需要,如:
固定结构,enjoy doing sth, look forward to doing sth;
时态结构:进行时:Look, the boying is playing with his mum. I was cooking when you called yesterday evening.
动词加ing作形容词:That was really exciting news. He's an interesting man.
动词作主语时,须变成加ing的动名词:Walking is good exercise. Playing a kite is fun.
希望对你有帮助
温馨提示:答案为网友推荐,仅供参考