I forgot something, so I'll go back and get it now.
以前、ある有名な受験参考書に「[忘れ物](https://eikaiwa.dmm.com/uknow/questions/31464/)をする」に forget は使えず、leave something somewhere（～をどこかに[置いたままにする](https://eikaiwa.dmm.com/uknow/questions/6383/)）を使わなければならない、と解説が載っているのを見ました。
しかし実際には forget something で「～をどこかに持っていくのを忘れる」を意味しますので、leave とは語法の面で違いがあるものの、日本語の「忘れ物をする」を表現するさいに forget を使っても問題ないわけです。
それと「今から」という日本語を from now と言う人が多いですが、ネイティヴの英語を観察していると、あまり from now という言い方はしないですね。
代わりに I'll do something (right) now. というほうがベターなようです。
例）I'll do my homework now.（今から宿題するよ。）
例）I'll take a nap now.（今からちょいと仮眠をとるね。）
I left something behind (he said, turning the car around)
Oh no! I left my car keys at home!
Usually, it would not be necessary to say that you need 'to go back to get' something as the context of the situation will make it clear to everyone that you are indeed going back.
John stopped walking and started feeling in his pockets desperately:
"Oh no! I left my car keys at home!" he exclaimed, retracing his steps.
文脈で取りに行かなければいけないというのは明白にわかるので、to go back to get とまで説明するのは 冗長でしょうね。
ジョンは立ち止まってポケットを突然まさぐりはじめた。
"Oh no! I left my car keys at home!" he exclaimed, retracing his steps.
I forgot my laptop at home. I have to go back and get it.
I have just realized that I forgot my laptop at home. I must drive back and get it.
Once in a while, you can forget something as useful at work as a laptop at home. When you get to the
office, you suddenly realize that your laptop is not in the car. This can cause you to panic. You have to inform your boss that you forgot your laptop at home and you have to drive back there and bring it. This has happened to me before. Forgetting your laptop at home can make you miss some deadlines due that morning.
I forgot (something). I'll go back home to get it.
「忘れ物をする」は
leave (something) at (place)
forget (something)
です。
I left my wallet at home.
I forgot my textbook.
というように使います。
I left (something) at home. I'll go get it.
= 家に（物）を忘れてきちゃった。取りにいってくるね。
I forgot (something). I'll go back home to get it.
=（物）を忘れちゃった。家に取りに戻るね。
"I'll be back in a minute", "I'll be back in a moment" denotes that you are going somewhere but will be back as quick as possible.
'Forgot' means that you did not remember something.
"I'll be back in a minute"
"I'll be back in a moment"
これらはちょっとどこかに行ってすぐ戻ります、と言う意味になります。
'Forgot' とは何かを忘れたという意味になります。
I forgot something at home, I need to go back and get it.
I left something at home, I'll go back and get it.
These three phrases can be used interchangeably to have the same effect but sometimes can be used in different contexts. The first example is something you would say to someone if you left a item not very far away. Like lets say, you just left a movie theater and you left your jacket :
- Hang on. I forgot my jacket, (in the theater) I'll be right back.
The other two examples can be used if something was forgotten or left and it was much further away from where you are most likely, so you need to explain to your friend that you, "need to go back and get it."
Ah I forgot something, I'll just pop back and get it
Oh I forgot my _____ let me just go back and get it.
I left my umbrella wait a moment while I go and get it
Ah I forgot something, I'll just pop back and get it
Oh I forgot my _____ let me just go back and get it.
I left my umbrella wait a moment while I go and get it
*You can also say...*
*I forgot my keys oh no! Can you just a wait moment while I fetch it?
*Oh my goodness I'm such a scatter brain, I forgot my..... could you just wait there a moment?*
Scatter brain= forgetful
*Ah I'm so forgetful, I left my bag at that restaurant...sorry, you guys go on, I'll catch you up*
'I'll catch you up' I'll walk/ run/ jog faster so I can walk next to you.
Hope this helps! ^ ^
Ah I forgot something, I'll just pop back and get it
あぁ、忘れ物をしたからさっと戻って取ってくるね。
Oh I forgot my _____ let me just go back and get it.
～を忘れたので、戻って取ってきます。
I left my umbrella wait a moment while I go and get it
傘を忘れたので、取ってくる間待っていてください。
以下のようにも表現できます。
*I forgot my keys oh no! Can you just a wait moment while I fetch it?
あぁ鍵を忘れてしまった！とってくる間少し待っていてもらえる？
*Oh my goodness I'm such a scatter brain, I forgot my..... could you just wait there a moment?*
あぁ私って本当にそそっかしい。～を忘れてしまった。そこで少し待っていてもらえる？
Scatter brain= 忘れやすい、そそっかしい
*Ah I'm so forgetful, I left my bag at that restaurant...sorry, you guys go on, I'll catch you up*
あぁ私って本当に忘れっぽいわ。レストランにかばんを忘れてきた。申し訳ないけど先行ってて。追いつくから。
'I'll catch you up'とは、自分が早く歩いたり、走ったりしてその人に追いつくことです。
"Oh no, I forgot something I'm going to go back to get it"
"I will be back soon, I need to go get something that I forgot"
If you have realised that you have forgotten something so you are going to go back to get it, you could say either of the following to express this: "Oh no, I forgot something I'm going to go back to get it" or "I will be back soon, I need to go get something that I forgot".
It completely slipped my mind, let me do it quickly.
I totally forgot about it, i'll get right to it.
It is very easy to forget something once in a while. This is okay, but you need to acknowledge your mistake and justify it and immediately tend to fix it.
The above two statements could be used to explain the situation.
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