There's no use in setting the alarm if you don't get up when it rings.
There's no point in setting an alarm if you're just going to go back to sleep.
目覚め時計 = an alarm clock -> the alarm
セットした時間 = the time you set
に = at
起きなきゃ = have to wake up -> unless I wake up
意味がない = there's no point / there's no use
もう一つの言い方は以下です。
Unless you get up when it goes off, why even set an alarm?
Don't bother setting an alarm if you aren't going to get up when it rings.
"Why do you bother setting an alarm, but you do not get up?"
Bother and get up mean
Bother - to take the time, the effort, or the trouble to do something, such as setting an alarm. So you should not bother or take the time to set the alarm if you are not going to respond to it.
Get up - To wake up from sleep and leave the bed.
To ask a question you could say you could rephrase the statement to ask,
"Why do you bother setting an alarm, but you do not get up?"
"Bother"と"Get up"の意味：
Bother - 時間・労力などをかけて何か（アラームをセットするなど）をする。鳴っても起きないのなら、わざわざアラームをセットすべきでないと言っています。
Get up - 眠りから覚めてベッドを離れること。
質問をするなら、以下のように言い換えられます：
"Why do you bother setting an alarm, but you do not get up?"
（起きないのならなんでアラームをセットするの）
What's the use of setting the alarm clock if you're not going to get up when it rings?
It makes no sense setting the alarm clock if you don't wake up when it rings.
Any one of these sentences can be used :-
1. What's the use of setting the alarm clock if you're not going to get up when it rings?
2. It makes no sense setting the alarm clock if you don't wake up when it rings.
When we use the phrases "what's the use....." or "it makes no sense to do....."means that we don't see the logic behind the action we are taking.
どちらの文も使えます：
1. What's the use of setting the alarm clock if you're not going to get up when it rings?（鳴っても起きないのなら何で目覚まし時計をセットするの）
2. It makes no sense setting the alarm clock if you don't wake up when it rings（鳴っても起きないのなら目覚まし時計をセットする意味ないよ）
"what's the use....."や"it makes no sense to do....."は、相手の行動の理屈が分からないときに使います。
"There's no meaning in setting an alarm clock if you don't wake up when it rings"
"There is no point in setting the alarm if you don't get up when it rings"
In order to explain that it is completely pointless to set an alarm clock if you don't wake up when it rings, you can state "There is no point in setting the alarm if you don't get up when it rings". This sentence explains that there is no logic behind creating an alarm if you will not use it for its purpose.
「鳴っても起きないのなら目覚ましをセットする意味はない」と伝えたいなら、次のように言えます。
"There is no point in setting the alarm if you don't get up when it rings".
（鳴っても起きないのなら目覚ましをセットしても仕方がない）
この文は「鳴っても起きないのなら目覚ましをセットする意味はない」という意味です。
It doesn't make sense to set an alarm if you don't wake up when it rings.
Why would you set an alarm if you aren't going to wake up when it goes off?
The two sentences you see provided above are terrific ways to express to your listener that there is no meaning in setting an alarm if you aren't going to wake up when it goes off. The second sentence is in the form of a rhetorical question. This type of question is used to emphasize a particular point or make a statement rather than get information.
Why would you set an alarm if you don't wake up when it rings?
I don't set an alarm because it doesn't wake me up
If you are talking to someone else where an alarm is ineffective say "Why would you set an alarm if you don't wake up when it rings?". This puts the emphasis on them to explain why the alarm doesn't work but they keep using it. If it is you than you can say "I don't set an alarm because it doesn't wake me up".
目覚まし時計の効果がないことを誰かに伝えるときには、"Why would you set an alarm if you don't wake up when it rings?"（目覚まし時計がなったときに起きないならどうしてセットするの？）と言うことができます。これは、アラームの意味がないのにどうして使い続けるのかと誇張した表現になります。
自分のことなら、"I don't set an alarm because it doesn't wake me up"（起きられないから、目覚ましをセットしない）と言うことができます。
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