第1个回答 2010-06-21
have +过去分词，就是一般完成时的构成形式。表示过去完成的事对现在的影响。
I have done my homework.
excite 表示 使......兴奋，是个动词。
excited 是个形容词 表示兴奋地，形容人的。
exciting 和excited 意思一样 是形容物的。
第2个回答 2010-06-21
have 加过去分词就是现在完成时态的结构之一
完成时构成有两种：
主语（是第三人称单数）+has+过去分词
He has lived here for many years.
主语（不是第三人称单数）+have+过去分词
They have lived here for many years.
excite是动词 excited和exciting 都是形容词前者一般是修饰人后者一般修饰物
He is excited.他很激动。
The game is exciting.这场比赛是令人激动的。
第3个回答 2010-06-21
这属于英语时态的一种形式．
英语的时态一共有16种；（四个时(time)；四个式(form)）.
四个时有：现在，过去，将来，过去将来
四个式有：一般，进行，完成，完成进行
因此，构成16个时态，下面是其结构：
一般现在时：用动词来表示（如果，主语是第三人称单数，将动词改为第三人称单数形式．如：do 为原型；does为第三人称单数形式）
一般过去时：用动词的过去是体现（动词的过去式有规则变法和不规则变法两种．（规则变法就是在动词后面加ed的那种；不规则变法，在教科书单词的后面有一页是表示动词不规则变法的）．
一般将来时：由助动词will/ shall＋动词原形构成
一般过去将来时：由助动词would/ should＋动词原形构成
现在进行时：由助动词be(am/is/ are)＋动词的现在分词表示．动词的现在分词，就是在动词后面按要求＋ing.
过去进行时：由助动词be(was/were)＋动词的现在分词表示．
将来进行时：由助动词will/ shall＋be＋动词的现在分词表示．
过去将来进行时：由助动词would/ should＋be＋动词的现在分词表示．
现在完成时：由助动词(have/has)＋动词的过去分词．动词的过去分词的变法跟动词过去式的变法相同．
过去完成时：由助动词had＋动词的过去分词．
将来完成时：由助动词will/ shall＋have＋动词的过去分词．过去将来完成时：由助动词would/ should＋have＋动词的过去分词．
现在完成进行时：由助动词(have/has)＋助动词been＋动词的现在分词表示．
过去完成进行时：由助动词had＋助动词been＋动词的现在分词表示．
将来完成进行时：由助动词will/ shall＋have＋助动词been＋动词的现在分词表示．
过去将来完成进行时：由助动词would/ should＋have＋助动词been＋动词的现在分词表示．
1.一般现在时：
eg. He goes to school by bike every day.
2. 一般过去时：
eg. He wrote a letter last night.
3.一般将来时：
eg. He will go to London next week.
4.一般过去将来时：
eg. He said he would go to London the next week.
5. 现在进行时：
eg. They are playing football there.
6. 过去进行时：
eg. He was doing homework at this time yesterday.
7. 将来进行时：
eg. He will be doing homework tomorrrow.
8. 过去将来进行时：
eg. He said he would be doing homework the next day.
9. 现在完成时：
eg. Tom has worked in that company for 5 years(=since 5 years ago).
10. 过去完成时：
eg. He said he had worked.
11. 将来完成时：
eg. He will have been in the army for 10 years by next June.
12. 过去将来完成时：
eg. He told them he would have finished by six o'clock.
13. 现在完成进行时：
eg. I have been reading all the morning.
14. 过去完成进行时：
eg. I was tired out; I had been reading for hours.
15. 将来完成进行时：
eg. By next summer, he will have been working here for 20 years.
16. 过去将来完成进行时：
eg. They told me that by the end of the year they would have been working together for 10 years.
excite vt. 刺激…，使…兴奋；激起 vi. 激动
eg. The rumors excite her curiosity. 谣言引起了她的好奇心。
The news excited us. 那消息使我们心情激动。
excited exciting区别：
我们把这类词看作是形容词，区别在于：＋ed的形容词，修饰人；＋ing的形容，修饰物．
excited adj. 激动的；兴奋的；活跃的
eg. Mom was very excited about my future too. 妈妈也对我的未来感到十分激动。
I know you must be very excited and happy. 我知道你一定会非常的激动,快乐的.
exciting adj. 使人激动的；令人兴奋的
eg. I have yet more exciting news for you. 我还有更令人兴奋的消息告诉你。
It was an exciting day. 这是非常刺激的一天。
It is exciting to visit different places. 拜访不同的地方是令人激动的。