An English grammer question

marrylovedog,
It is correct that some nouns must be used in plural such as tongs, trousers,spectacles,scissors etc., meaning that 's' or ' es' must be added to the noun concerned because it has two parts forming a kind of pair, like a pair of scissors, a pair of specticles, a pair of trouses. However, if you look at the following examples, you may agree with me that " It is my binoculars " is correct other than " They are my my binoculars ".

A pair of trousers.'A' 是文法上叫indefinite article不明確冠詞,' a pair of trousers'是 文法上叫noun phrase, 幾個字代表的一件東西；所以你指着一條褲對店員說" They are so beautiful ! I want to buy them "是錯的。因為一條褲雖由兩褲管合成一物,但還是不可分割來用的單一件東西。應說成 " It is so beautiful ! I want to buy it."

The iron scissors. ' The' 是文法上叫 definite article明確冠詞,'a pair of scissors' 同樣是文法上叫noun phrase, 幾個字代表的一件東西；所以你指着那剪刀對店員說 " I like them, will you show them to me?"也如上句是錯的。因為剪刀雖由兩片刀合成,但也是不可分開來用的單一件東西。應說成 " I like that scissors. Will you show it to me please." 其餘像鉗(tongs),細坺毛鉗(pincers)也如是。

例外的是A pair of boots 或 shoes或 gloves等 因為它們不是連體的但要一起穿才有用就必要寫或說成 " How do you like this pair of shoes ? They are mine." 或指着一對靴對店員說 " They are beautiful. Will you please show them to me."

建議你一個永遠可行的方法：

It is my pair of binoculars.

It is my pair of pants/jeans.

It is my pair of scissors.

反過來寫亦一樣做法：

I have a pair of binoculars.

I have a pair of pants/jeans.

I have a pair of scissors.

當然這些是合規格和傳統的寫法。

假如口語則未必要咁。
不過我一般聽外國人都會用眾數的代名詞。

These are my pants!只係講緊一條褲。

marylovedog
Your question has got the answer already. Things born plural remain plural for life.

I will use
Its my binocular

in this time you don't have to use "s"
because it is one thing, which is not two

They are my binoculars