When listening to a foreign language it can be hard to understand what the other person is saying as they are speaking too fast.. Sometimes you will need to ask the other person "Please speaker slower.", "Please speak slowly.", or "Please speak more slowly.".
Could you speak a little slower so that I can understand you, please?
"Could you" is a nice way to ask someone to do something. In this case, you are asking them to speak more slowly so that you can understand.
I hope that this helps :)
Native speakers will say like this: “Could you speak more slowly?”.
There are lots of other ways to say it, but this one is the most accurate and most commonly used.
Here is an example on how to use this in a conversation:
A: Sorry, could you speak a bit slower?
B: Oh, my bad. Of course I can!
ネイティブスピーカーなら次のように言います。
“Could you speak more slowly?”
（もう少しゆっくり話してもらえますか）
他にもいろいろな言い方ができますが、これが最も正確で一般的です。
以下、会話例です。
A: Sorry, could you speak a bit slower?（すみません、もう少しゆっくり話してもらえますか）
B: Oh, my bad. Of course I can!（あ、ごめん。もちろんいいですよ）
Could you please speak a bit slower? I'm finding it hard to understand when you are speaking fast
Please speak slowly.
Please slow down your speaking speed
When you are trying to explain to someone that it's hard for your to understand English when they speak too fast, then you can say:
-Could you please speak a bit slower? I'm finding it hard to understand when you are speaking fast
-Please speak slowly.
-Please slow down your speaking speed
相手が速く話すと英語を理解するのが難しいと説明したいときのフレーズです。
-Could you please speak a bit slower? I'm finding it hard to understand when you are speaking fast
少しゆっくり話してもらえますか？はやく話すと理解するのが難しいのです。
-Please speak slowly.
ゆっくり話してください。
-Please slow down your speaking speed
話すスピードをゆっくりにしてください。
If someone speaks quickly you might not always get/understand everything they say so the best thing to so is ask them to slow down for you
'could you speak a little slower please?' or 'Please can you speak more slowly' these are both nice polite ways of asking with not offending anyone as well
早口で話されると、相手の言ったことが全て聞き取れない（理解できない）こともあるかもしれません。こういうときは、ゆっくり話して欲しいとお願いするのが一番です。
'Could you speak a little slower please?'（もう少しゆっくり話してもらえますか）
または、
'Please can you speak more slowly'（もう少しゆっくり話してもらえますか）
これらはどちらも、相手を不快な気持ちにさせることのない丁寧な言い方です。
Could you slow down please - it's a little fast for me to understand?
When anything is going to fast - a car, fairground ride, or someone speaking, you may request that the person or thing 'slow down'.
Eg. 'You're driving too fast. Please slow down!'
オーストラリア 
ブルガリア 
アメリカ合衆国 
カナダ 
南アフリカ 
イギリス 
