Your coffee will cool down if you don't drink it soon
If you leave a cup of tea/coffee for a while it will not be so hot we call this to 'cool down' or to 'get cold'
To do something soon means to do it in a short period of time or quickly in time
I like my coffee hot so I need to drink it now before it cools off.
You may want to drink your coffee while it's still hot.
Making your statement sound more like a request is polite and makes them think you are watching out for them.
Let's drink our coffee while it's still hot.
I like my coffee hot so I need to drink it now before it cools off.
You may want to drink your coffee while it's still hot.
Do you need me to refresh your coffee for you?
単に事実を述べるのではなくお願いのようにすると丁寧になり、相手のことを気にかけてくれていることが伝わります。
Let's drink our coffee while it's still hot.
（温かいうちにコーヒーを飲みましょう）
I like my coffee hot so I need to drink it now before it cools off.
（温かいコーヒーが好きなので、冷める前に飲まないと）
You may want to drink your coffee while it's still hot.
（温かいうちにコーヒーを飲んだ方がいいかもしれませんよ）
Do you need me to refresh your coffee for you?
（コーヒー入れ直そうか）
"You may want to drink your coffee while it's still hot"
"It would be a good idea to drink your coffee before it cools down too much"
If you wanted to tell someone that they should drink the cup of coffee they have due to it getting cold, you can simply state, "Your coffee is getting cold", "You may want to drink your coffee while it's still hot" or "It would be a good idea to drink your coffee before it cools down too much". All three of these sentences express that you believe drinking the coffee soon as its cooling down is a good idea.
コーヒーが冷めてきているので飲んだ方がいいと伝えたいなら、次のように言えます。
"Your coffee is getting cold"（コーヒー冷めてきているよ）
"You may want to drink your coffee while it's still hot"（冷めないうちにコーヒーを飲んでください）
"It would be a good idea to drink your coffee before it cools down too much"（冷めないうちにコーヒーを飲んだ方がいいですよ）
どの文でも、冷めてきているので早くコーヒーを飲んだ方がいいと伝えることができます。
The two sentences you see provided above are excellent ways to express to your listener that their cup of coffee is going to get cold. In the second sentence you will see the term cup of Joe. This is an informal way of referring to coffee. This term would be appropriate for informal settings, like talking with close friends or family.
上記二つの例文は、「コーヒーが冷めるよ」と伝える素晴らしい言い方です。
二つ目の例文には、"cup of Joe" という表現が使われています。これは「コーヒー」のインフォーマルな言い方です。この表現は家族や親しい友人と話すときなどインフォーマルな場面に適しています。
The most simple way of saying this is "Your coffee is getting cold.". However, this is probably the least friendliest way of saying that they should drink their coffee. The other two sentences are more friendly. "Drink up" is a phrase often used in England which means "finish your drink".
最もシンプルな言い方は、"Your coffee is getting cold."（コーヒーが冷めてきているよ）です。ただ、たぶんこれは最も愛想のない言い方でもあります。
他の二つの文はもっとフレンドリーです。
"Drink up" はイングランドでよく使われるフレーズで「飲み干す」という意味です。
Your coffee will be cold by the time you decide to drink it
When you want to remind someone that their cup of coffee is getting cold because they are not drinking it, then you may express it in the following ways:
-Your coffee is getting cold.
-Your coffee will be cold by the time you decide to drink it
コーヒーが冷めてきていると知らせたいなら、次のように言えます。
-Your coffee is getting cold.（コーヒーが冷めてきてますよ）
-Your coffee will be cold by the time you decide to drink it（飲む頃にはコーヒーが冷めてしまっていますよ）
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