簡單一個英文單字的問題*英文人help!!!

1. 文法上冇分別，句法上可能用myself/yourself/itself來加強語氣
I commit to our relationship
I commit myself to our relationship
基本意思一樣

2. infinite
I commit to do something

3. 像一般男人，他往往不能承諾認真對待一段關係(意思是不能專一)。

Commit ~ to say that someone will definitely do something or must do something
(使表態, 使承擔義務, 把...交託給, 委托, 把...判處)

有下列各項 format:
(1) Commit somebody to something
The judge committed him to ten years' imprisonment. (法官判處他十年徒刑)

(2) Commit oneself
I asked her what she thought, but she refused to commit herself.
我問她是怎麼想的，但她拒不表示意见。

(3) Commit oneself to (doing) something
He didn't commit himself to anything. (他沒有作任何承諾)
I have already committed myself to working for John. (我已經承諾為約翰工作了)

Beware:
Commit oneself to doing something, 不是Commit oneself to do something
To 不是做 infinitive, 在這裡是 preposition. 所以使用 -ing form.
其他類似的例子:
I look forward to seeing you.

第三句子的 commit這個字有 slightly different meaning. (答應負責)

Commit - to give someone your love or support in a serious and permanent way.
e.g. My girlfriend wants to get married, but I am not so sure I want to commit.

Like many men, he has problems committing himself to a relationship.
像許多男人，他自己有問題肯去承擔一種關係. (暗示他無認真,玩玩下,even做好朋友間的友誼不能持續很久)

commit 還有其他 meaning, (犯(罪), 做(錯) commit crime, commit suicide