英语及物动词和不及物动词我看了书上和百科的解释：后跟宾语就是vt,不根就是vi那我就问了,一个行为动词是vt还是vi是否是由后跟宾语来决定的?如果是由后跟宾语来决定的话,那我在一个行为动词后放一个宾语我就说他是vt了,不放宾语我就说他是vi了?就拿write来说,查字典显示即是vt又是vi,那他凭什么说他是vt又是vi,这不完全取诀于是否后跟宾语吗另外I write这句话语法对不对,I和write不是构成主谓结构了吗?

是否是及物动词，与英语文化的底蕴有关。不是我们汉语能解释的了得。是一种语言习惯。比如，我看了看你。中文看是及物动词。而英文中就不及物。得用look at.其实没什么规则。
write具备及物、不及物、瞬间、延续四大特点。
i wrote a letter.及物
i wrote to him.不及物
i am writing a letter now.延续
he has written to me.瞬间
i write.正确。i play. i write. i eat. i drink.都是主谓结构。

用 "eat" 更容易理解 vt 和 vi 的区别:
A. eat : vt
1. A plant that eats insects.
2. He stops eating red meat.
3. an acid that eats the surface of a machine part.
4. You can eat your loss and switch the remaining money to other investment portfolios.
5. She was eating a banana.
B. eat: vi [ object] 没有后跟宾语
1. We did not eat until 10 P.M. because there were so many phone calls;
2. I didn't eat yet, so I gladly accept your invitation.
=========================================================
A. write : vt
1. How do you write your name?
2. write a poem; write a check (cheque); write a will...
3. Mary wrote that she was planning to visit us next month.
4.It was written that the empire would fall.
5. He wrote four novels in a year.
B. write: vi
1. Why didn't you write (没有后跟宾语) and let me know you were coming?
2. I can't write. 没有后跟宾语

动词及物不及物的标准是看是否能够加宾语.就是说如果一个动词加宾语后结构才完整,那么这个动词就是及物动词,比如I read a book这个read是及物动词,所以a book这个宾语一定要加.反过来如果一个动词如果不加宾语结构就...