"I am very happy to visit the factory."为什么后面的动词不定式不能换用动名词

I am very happy to have you! I am very happy to work here I am very happy i am very happy to have chance to be I am feeling very happy I am very happy to have you with me I am very happy to meet you Thank you Darling .I am very happy to be your wife . I am very happy 对very happy 提问 Baby,you must be very very happy.I am willing with mine all,to trade you to be happy! 英语翻译I want to let you know that I am very happy to get your email. 英语翻译have you,i am very happy I am very happy this holiday. i am very happy today句子成分划分 Have you,I am very happy i am very happy with you I AM VERY HAPPY BEAUSE FOR YOU I am very happy tonight是什么意思