1.competition是指技巧,体能,知识等的赛事.

eg.There will be a competition to find a designer for the new airport building this afternoon.

2.game 指游戏,运动,比赛,可以是户内或户外的,也可以的脑力的,还可以的体力的,通常有一定规则,如球赛等.

eg.If you win this game you will win the whole match.如果你赢了这一局,你将赢得整场比赛.

3.play 可以指游戏,娱乐,也可以指比赛,竞赛.

eg.In sports , exercise and play are not divorced . 在运动中,练习和比赛是分不开的.

另外,play 作为动词使用的情况比较多.

eg.I love playing computer games . 我喜欢玩电脑游戏.

Your school plays against us this afternoon . 你们校队今天下午和我们比赛.