「時間を忘れるぐらい」は英語では to forget about the time と言います。
例えば
I had so much fun, I completely forgot about the time.
楽しすぎて、時間を完全に忘れた。
I had so much fun that time passed too quickly.
楽しすぎて、時間が経つのが早かった。
英語でのことわざがあります。Time flies when you're having fun です。楽しんでいる時こそに、時間が早く経ってしますと言う意味です。
＜ボキャブラリー＞
forget = 忘れる
time = 時間
quickly = はやく
ご参考までに。
The idea of 'time flying' when we have fun is something of a cliche, however, it is a popular phrase in many various forms. 'To lose track of time' means to forget about the passing of time to the extent that you do not appreciate what the actual time is.
何か楽しいことをしている時の"time flying"という概念は決まり文句のようなものですが、様々な形で表現されるポピュラーなフレーズです。
"To lose track of time"とは、時間が経つのを忘れてしまうことを意味します。
We were having so much fun, I forgot what time it was!
As a native English speaker, I would say: "It was so much fun that I forgot about the time." or "We were having so much fun, I forgot what time it was!". Both of these examples explain how you were immersed in the activity and forgot to even look at the time. "Time flies when you're having fun!" is an example of a saying in English that describes the same thing.
英語のネイティブスピーカーとして、私だったら次のように言います。
"It was so much fun that I forgot about the time."（時間を忘れるくらい楽しかったです）
または、
"We were having so much fun, I forgot what time it was!"（時間を忘れるくらい楽しかったです）
どちらの例も、時間を確認するのを忘れるくらいそれに夢中になっていたという意味です。
"Time flies when you're having fun!"（楽しい時間はあっという間に過ぎていく）は、同じことを伝える英語のことわざです。
"Time goes quick when you're having fun" is a very popular English saying and can be used in a variety of situations. You could use this after a lesson, after a meeting or after just spending time with friends.
"Time goes quick when you're having fun"（楽しい時間はあっという間に過ぎてしまう）―このフレーズは、とてもポピュラーな英語表現で、様々なシチェーションで使えます。
例えば、レッスンの後、ミーティングの後、または、友達と時間を過ごした後などで使えます。
"Time goes so quickly when you are having a lot of fun"
"We were having so much fun, time just flew by so fast"
If something was so fun that you forgot about the time, you could explain this by stating any of the following: "It was so fun that I forgot about the time", "Time goes so quickly when you are having a lot of fun" or "We were having so much fun, time just flew by so fast". All three of these sentences adequately explain that you were enjoying yourself so much that you forgot about the time.
時間を忘れるくらい楽しかったことは次のように表せます。
"It was so fun that I forgot about the time"（時間を忘れるくらい楽しかったです）
"Time goes so quickly when you are having a lot of fun"（楽しい時間はあっという間に過ぎていきますね）
"We were having so much fun, time just flew by so fast"（すごく楽しくて本当にあっという間でした）
上記どの例を使っても、それが時間を忘れるぐらい楽しかったことを伝えることができます。
I didn't realize what time it was because it was so fun!
When someone says "time is flying by"(present) or "time flew by" (past) that means that the time went really fast.
To "lose track of time" (present) or "lost track of time" (past) is to forget what time it is or forgot about the time completely. "Lost track" can be used in other situations to say you don't know what's happening anymore or you stopped counting, for example "how many chocolates have you eaten today?" - "I don't know, I lost track".
"I did not realize what time it was" is a way to say that you forgot about the time and you did not see the time.
Another popular phrase is "time flies when you're having fun" which means when you are happy and enjoying yourself, time will move faster.
"time is flying by"（現在）または "time flew by"（過去）は「時間があっという間に過ぎた」という意味です。
"to lose track of time"（現在） または "lost track of time"（過去）は「何時か分からなくなる［分からなくなった］」という意味です。
"lost track" は「現状が分からなくなる」「数が分からなくなる」という意味で、これ以外の場面でも使われます。
例えば：
"How many chocolates have you eaten today?" - "I don't know, I lost track".
「今日チョコ何個食べたの」「知らない。数え切れなくなった」
"I did not realize what time it was" は「時間がたつのを忘れた」という意味です。
また、"time flies when you're having fun" も一般的なフレーズです。これは「楽しい時間はあっという間に過ぎる」という意味です。
The phrase 'time flies when your having fun' means that if you are enjoying something then time seems to pass by quickly'
To forget all about the time means it has gone quickly and you didn't realise what the time was
Time flies when your having fun' は「楽しいことをしていると時間はあっという間に過ぎていく」という意味です。
'To forget all about the time' は「あっという間で、時間が経つのを忘れた」という意味です。
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