請問動名詞和不定詞的差別?

Seeing is beliveing

今天要分享的俗諺是 “Seeing is believing”「眼見為憑」。 「更多英文學習：QQ English」
上禮拜我們談到英文的名詞，這禮拜來談另一種形式的名詞：動名詞。 顧名思義，動名詞具有「動詞的外表」，但卻有「名詞的內涵」，由「原形動詞＋ing」所形成， 例如俗諺中的seeing、believing。為什麼英文會有動名詞呢？ 英文文法有一個非常重要的觀念，就是「一個英文句子只能有一個名詞、一個動詞」， 如果有兩個以上的動詞，就必須想辦法解決。其中一個辦法就是把其他動詞＋ing， 使其變成「動名詞」。 動名詞有幾種功能，其中兩種是作為主詞、補語。以這禮拜分享的俗諺Seeing is believing為例， 我們一起分析這段句子的文法結構：
seeing是動名詞，作為主詞。see原本是動詞，不能直接當成主詞，所以一定要＋ing，變成動名詞（seeing），才能作主詞。
is是動詞（所謂的「be動詞」）。分析到這邊，我們確定這句俗諺有了英文句子最重要的兩項元素，就是主詞、動詞。這邊提醒大家，分析英文句子的文法時，先找出它的主詞、動詞；少了一項，這個句子的文法一定不對。
所以seeing is.....，目前這段句子的意思並不完整，而「believing」這個動名詞就作為補語，補充說明主詞的狀態。為什麼要接動名詞呢？上面提到，這是因為一個英文句子只能有一個動詞阿。

The difference between the infinitive and the gerund are:-
(1)The gerund has form and are formed with -ing like the present participle (active and passive)
Function:- are used as nouns
eg:-
Seeing is believing.
I like playing a game of mahjong.
Not being married is one of man's most unfortunate conditions, another is having a wife.
Loud talking is forbidden in a library.
He objected to his being hurt by a rioter without seeing the mask-face ?!
(2)The infinitive has a form in the following table showing the various forms of infinitive"to take":-
eg:-to take---present active
to be taken---present passive
to have taken---perfect active
to have been taken----perfect passive
Function:-as a noun:-
eg:-To hate is human....To forgive is divine or divine.
They wanted to visit the Queen.
Used as an adverb:-eg:-
He was angry to have been cheated by the gang.
used as an adjective:-
eg:-
We students have a lot of work to do.
These books are not to be taken away from the Library.
Used as Infinitive without "to";eg:-
Let it go ; let it go; now ?!
I heard the choir sing.
Elsa and Anna watched the film-team win the Oscar festival honor.
-----The Infinitive without "to" are used after verbs like :-eg:-let, hear, watch, make, see.
And after auxiliary verbs like:-eg:-can, could, shall, should, will, would, may, might, do, does, did, etc.
eg:-She does not see the film called "frozen-freeze" because she is poor ?!

一個在結構上是[verb]-ing，另一個是to [verb]
不過前者是用於已完成的動作，而後者就是未完成或者未成立的(即是想做的)，例如


動名詞：I enjoy swiming.
不定詞：I want to swim.