「必要ない」は英語では普段"unnecessary"といいます。例えば「この靴は必要ない」は"These shoes are unnecessary."となります。（逆に"necessary"は「[必要](https://eikaiwa.dmm.com/uknow/questions/32984/)」という意味です）
さらに、"need"は「必要」に相当するので"don't need"は「必要ない」となります。
"I don't need this."
「私はそれを必要としない」
参考になれば幸いです
No need, is a very common phrase that is used when replying to something that is unnecessary.
"Hey, should I bring an extra jacket?"
"No need. We won't be there for long."
Also, "you don't have to" is another phrase that is used with the same meaning.
Hope this helps!
"No need"は、必要がないことに返答する場合にとてもよく使われます。
例文
"Hey, should I bring an extra jacket?"
"No need. We won't be there for long."
↓
「ねぇ、予備のジャケット持って[いった方がいい](https://eikaiwa.dmm.com/uknow/questions/15907/)かな？」
「必要ないよ。そこに長くはいないから」
また、"You don't have to"というフレーズも、同じ意味で使われます。
お役に立てば幸いです。
That's pointless, you don't need an extra pair of shoes.
Bringing an extra pair of shoes is non-essential.
The two sentences you see provided above are excellent ways to express to your listener that something is not necessary, like bringing an extra pair of shoes on vacation. In the first sentence you will notice the adjective pointless and in the second sentence you will notice the adjective non-essential. Both of these words mean unnecessary.
It's not necessary to bring an extra pair of shoes
It's Unnecessary to bring an extra pair of shoes
An extra pair of shoes are not needed
To say ' not necessary', 'unnecessary' or 'not needed' all mean the same thing
So you could say ' It is not necessary to bring an extra pair of shoes with you'
「not necessary」「unnecessary」「not needed」、どれも同じ意味です。
ですから、以下のように言えます：
'It is not necessary to bring an extra pair of shoes with you'
（予備の靴を持って来る必要はありません）
You want to say that something is "not necessary" ? For example, when someone asks you if they should bring an extra pair of shoes on vacation, you want to say that it is "not necessary". In the UK we would often say 'Don't bother' instead of 'it is not necessary'.
"not necessary" とは必要ないという意味です。例えば、旅行に予備の靴を持っていくべきかどうか尋ねられて"not necessary"と言うことができます。イギリスでは、'it is not necessary'の代わりに 'Don't bother'と言います。
The first two answers involve expressing that something will not be useful or necessary. As a result, the person doesn't need to bring that item, or do that action, etc.
The third answer is a common way for you to say that the decision can be made by the person themselves and that it will not have much of a significant impact. In other words, It's not going to make a big difference which thing they choose to do.
You can use either not necessary or unnecessary. Both terms have the same meaning but they offer different connotations. Both explain that something is not required.
For example: "An extra pair of shoes is not necessary".
Or you could simply add that it is not needed.
For example: "You don't need an extra pair of shoes".
「not necessary」か「unnecessary」が使えます。どちらも同じ意味ですが、ニュアンスは変わります。どちらも、必要がないことを表します。
例：
"An extra pair of shoes is not necessary".
（予備の靴は必要ありません）
「need」を使って言うこともできます。
例：
"You don't need an extra pair of shoes".
（予備の靴は必要ありません）
Your actions were very unnecessary. Apologize immediately.
It is unnecessary for you to do that. We don't need it any longer.
I don't think that is necessary. We can throw it away.
必要ない unnecessary, not necessary
あなたの行動は非常に不必要でした。 すぐにお詫び申し上げます。
Your actions were very unnecessary. Apologize immediately.
あなたがそれをする必要はありません。 もう必要ありません。
It is unnecessary for you to do that.
We don't need it any longer.
それは必要ないと思います。 捨てることができます。
I don't think that is necessary. We can throw it away.
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