I will be sure to respond to you promptly the next time.
I will try to get back to you sooner from now on.
ビジネスシーンで使う言い方なら、例文１のような言い方良いかなと思います。
「次は必ず迅速に返信します。」というニュアンスです。
I will be sure to 〜で「必ず〜します」という言い方です。
promptly は「速やかに・迅速に」という意味です。
そこまでかしこまらなくて良い場合なら、例文２が良いかと思います。
「今後はもっと早く返事をするようにします。」というニュアンスです。
get back は「後で連絡をする」という意味で、try to get back to you sooner で「もっと早く（折り返しの）連絡をするようにする」というニュアンスになります。
ご参考になれば幸いです！
Im sorry the reply took so long, I will try reply sooner in the future.
Im sorry the reply look a while, I will try reply more promptly in the future.
"I'm sorry the reply took so long, I will try to reply sooner in the future." This explains to the person that you are sorry for the time of the last reply and you will try to be quicker in the future.
"I'm sorry the reply took a while, I will try to reply more promptly in the future." This is a more formal way of explaining that you are sorry that the first reply taking so long and you will be quicker in the future.
"I'm sorry the reply took so long, I will try to reply sooner in the future."
返信に時間がかかってすみません。これからはすぐに返事をするようにします。
これは、相手に返信に時間がかかって申し訳なく思っていて、これからはもっとはやく返信するようにすることを伝える表現です
"I'm sorry the reply took a while, I will try to reply more promptly in the future."
返信に時間がかかってすみません。これからはもっとはやく返信するようにします。
これは、返信に時間がかかって申し訳なく思い、これからはもっとはやく返信するようにすることを伝えるよりフォーマルな表現です。
I'll make an effort to respond more quickly next time
Well, it may be better to indicate that you will try to respond more quickly next time (rather than promise that you will). You do not know what future distractions may arise so to make a guarantee at such an early stage may be foolhardy!
I apologise for my belated response, I will be more punctual in the future.
I am sorry for my tardy response, I will respond quicker next time.
Sorry it took me so long to write back. I will write back quicker from now on.
"Belated" means that something happened later than it was supposed to. If I forgot my friend's birthday, and said "Happy Birthday" one week late I could say "Sorry for the belated birthday wishes.". "Tardy" is another way to say "late".
"I apologise for my belated response, I will be more punctual in the future." uses formal language that is appropriate for the workplace. "I am sorry for my tardy response, I will respond quicker next time." is a more informal way to say this. "Sorry it took me so long to write back. I will write back quicker from now on." is very casual language that you would use with friends.
「Belated」は「遅れた」という意味です。例えば、友達の誕生日を忘れていて「Happy Birthday（誕生日おめでとう）」を1週間遅れで言ったとしたら：
Sorry for the belated birthday wishes."
（誕生日のお祝いが遅くなってごめんなさい）
と言えます。
"I apologise for my belated response, I will be more punctual in the future."
（返信が遅くなってすみません。次回はもっと早くするように致します）
- これはフォーマルな言い方で、職場で使うのに適しています。
"I am sorry for my tardy response, I will respond quicker next time."
（返信遅れてすみません、次はもっと早く返します）
- こちらの方がインフォーマルです。
"Sorry it took me so long to write back. I will write back quicker from now on."
（返信遅れてごめん。これからはもっと早く返します）
- これは、友達に使うようなとてもカジュアルな言い方です。
I will try my best to respond promptly from now on
I'll try reply quickly from now on
I will be quick with my responses in the future, starting now.
When you're trying to tell someone that you are going to respond to their messages quickly from now on, then you can say:
-I will try my best to respond promptly from now on
-I'll try reply quickly from now on
-I will be quick with my responses in the future, starting now.
これからは早く返信するようにすると伝える言い方です：
I will try my best to respond promptly from now on.
（これからは早く返信するようにします）
I'll try to reply quickly from now on.
（これからは早く返信するようにします）
I will be quick with my responses in the future, starting now.
（これからは早く返信するようにします）
Sorry for the late reply, I will be able to reply quickly from now on.
Sorry for the delayed response, I will be sure to respond to you promptly from now on.
Both of these sentences are saying the same thing. The first sentence is more informal, something you would probably say to a friend if you have taken a while to respond to their message. The second sentence is more formal, something you may want to put in an email.
I will make sure to get back to you more quickly next time.
I'll try to respond asap this time!
"I will make sure to get back to you more quickly next time." is a polite way of saying that you will try to respond in a more timely manner next time you reply. "I'll try to respond asap this time!" is a more casual way to let the other person know that you'll be making an effort to reply "asap" = "As Soon As Possible".
Hope this helps! :)
"I will make sure to get back to you more quickly next time."（次はもっと早く返信するようにします）
これは「次はもっと速やかに返信するようにします」と伝える丁寧な言い方です。
"I'll try to respond asap this time!"（今回はできるだけ早く返信するようにします）
これは「できるだけ早く返信するようにします」と伝える、カジュアルな言い方です。
"asap" = "As Soon As Possible"（できるだけ早く）
参考になれば幸いです！
I'll try to reply as soon as possible from now on.
I will reply promptly from now on.
If you want to say that you will try to reply quickly from now on, you can say:
"I'll try to reply as soon as possible from now on."
"I will reply promptly from now on."
「これからは早く返信するようにする」は次のように言えます。
"I'll try to reply as soon as possible from now on."（これからはできるだけ早く返信するようにします）
"I will reply promptly from now on."（これからはすぐに返信します）
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