look forward to中的to是介词，表：期待、盼望时，后面只能跟名词或动名词，因此只能加doing，不能加不定式to do。
look forward to
读音：英 [lʊk ˈfɔːwəd tu] 美 [lʊk ˈfɔːrwərd tu]
释义：期待，盼望。
语法：基本意思是“期待”“料想”，指相信或盼望有人会来或有事会发生，这种预料多有一定的根据，强调的是客观可能性，多用于好的方面。
例句：
Well, we shall look forward to seeing him tomorrow.
嗯，我们期待着明天与他会面。
扩展资料
look forward to的近义词：expect to
expect to
读音：英 [ɪkˈspekt tu] 美 [ɪkˈspekt tu]
释义：期待。
语法：expect多用作及物动词，可接名词、代词、动词不定式或that从句作宾语，也可接以动词不定式充当补足语的复合宾语。
例句：
Don't overspend on your home and expect to get the money back when you sell.
不要在买房子上超支并指望以后出售时还能把钱赚回来。
look forward to 后面只能跟 动名词或名词，只有look forward to do
跟 to do的词：
1、afford to do sth 承担得起做某事
His mother couldn’t afford to pay for her child’s education.他母亲承担不起自己孩子的教育费用。
2、agree to do sth 同意做某事
Mum and Dad have agreed to have a party at home.妈妈和爸爸已经同意在家里举办一次聚会。
3、aim to do sth 目的是做某事
The class aims to teach the students how to play basketball.这节课的目的是教这些学生如何打篮球。
4、appear to do sth 好像 / 似乎做某事
She appears to have many friends.她好像有很多朋友。
5、arrange to do sth 安排 / 计划做某事
We arranged to meet at 7:00 to play football. 我们计划七点集合去踢足球。
6、ask to do sth 要求做某事
The boy asks to go to school by bike.这个男孩要求骑自行车去上学。
7、choose to do sth 选择做某事
Half of the students choose to go to big cities.一半的学生选择去大城市。
8、decide to do sth 决定做某事
He decided to be a firefighter.他决定当一名消防员。
9、expect to do sth 期望做某事
You can’t expect to learn a foreign language in a few months.你不要指望在几个月内就能学会一门外语。
10、fail to do sth 没能做某事
He looks so different that they fail to recognise him.他看上去大不一样，结果他们没认出他来。
扩展资料：
后面接doing：
1、admit doing sth.承认做某事
2、allow doing sth.允许做某事
3、avoid doing sth.避免做某事
4、delay doing sth.推迟做某事
5、discuss doing sth.讨论做某事
6、enjoy doing sth.喜爱做某事
7、admit doing sth.承认做某事
8、excuse doing sth.原谅做某事
9、finish doing sth.完成做某事
10、forgive doing sth.原谅做某事
11、imagine doing sth.想象做某事
12、mention doing sth.提及做某事
13、miss doing sth.错过做某事
14、permit doing sth.允许做某事
15、prevent doing sth.阻止做某事
16、put off doing sth.推迟做某事
17、risk doing sth.冒险做某事
18、suggest doing sth.建议做某事
本回答被网友采纳I am looking forward to seeing you soon. = I expect to see you soon.
I am looking forward to your early reply. = I extpect to receive your reply.
而且 一般都是 be looking forward to doing sth 表示一直期待的意思。本回答被提问者和网友采纳