动词分三类，表达分六种
三类：be动词有名无实；实义动词有名有实；分词无名有实。
六种：以喜欢like为例：Like-likes-liked；To like-liking-liked。以吃eat为例：Eat-eats-ate；To eat-eating-eaten
1.Tyger likes apples.
2.Tyger liked apples.
3.Tyger likes eating apples.
4.Tyger likes to eat apples.
5.Tyger liked eating apples.
6.Tyger liked to eat apples.
基本时态分五种，完过一将进
1.Tyger have eaten apples.
2.Tyger ate apples.
3.Tyger likes apples.
4.Tyger will like apples.
5.Tyger is eating apples.
TYGER
