为什么see的过去式是sew？
see的过去式是saw。因为see属于不规则动词。
英语采用的是变形法，即不加ed，而是让动词本身发生变化，如：eat变成ate，see变成saw，ate、saw就是表达“吃过了”、“看过”的过去式。
过去式用来表达动词的“过了”、“完了”等意思，汉语里表达动作的时间时采用的是前后加字法，即在动词的前面或后面加字，如表达做过和做完，只要在动词的后面加上“过了”、“完了”就行了，如吃过了，看到了……
see的用法：
1、指用眼晴“看见某事物，或注意到某事物。
You can't see colours at night. 晚上看不见颜色。
I saw a man making his way towards me. 我看到一名男子向我走来。
She can see, hear, touch, smell, and taste. 她有视觉、听觉、触觉、嗅觉和味觉。
As he neared the farm, he saw that a police car was parked outside it. 他走近农场时,看到一辆警车停在外面。
Did you see what happened? 你看到发生什么事了吗？
2、指看见、会见或访问了某人。
I saw him yesterday. 我昨天见到他了。
Mick wants to see you in his office right away. 米克要你马上去他的办公室见他。
You need to see a doctor. 你需要去看医生。
3、看戏剧、电影、音乐会或体育比赛等娱乐节目，意为“观看、参观”。
He had been to see a Semi-Final of the FA Cup.
他看过一场足总杯半决赛。
It was one of the most amazing films I've ever seen.
这是我看过的最精彩的电影之一。
I've got nothing to do this evening. I think I'll see a film.
今晚没事儿，我想去看电影。
4、指领会、查觉到某事是存在的或真的。
I could see she was lonely. 我能看出她很寂寞。
You see young people going to school inadequately dressed for the weather.
你看到年轻人在这种天气里衣衫单薄地去上学。
