Is that your honest opinion?
Honest means to be truthful and sincere, by using this word you are asking them to reveal their true opinions and not to be deceitful or insincere. You are asking the speaker to confirm that they genuinely believe what they are saying.
The word genuinely can be used in the same way as honest (honestly) when asking questions about what people really think. Genuine has a number of meanings. One meaning is being honest and truthful.
"I genuinely believe Brexit is a complete disaster."
例文：
Is that your honest opinion?
（これはあなたの正直な意見ですか？）
Honestとは真実かつ誠実であることで、この言葉を使うことで相手に騙しや不誠実さのない真実な意見を明かしてくれるように頼んでいます。話し相手に言った自分の言葉を本当に信じているか確認するように尋ねているのです。
Genuinelyという言葉は相手が本当に考えていることを尋ねる際にhonest (honestly)と同じように使えます。Genuine は幾つかの意味がありますが、その一つは正直で真実であることです。
例文：
"I genuinely believe Brexit is a complete disaster."
（私はブレクスィットは完全な失敗だと心の底から考えています。）
"Do you really believe that?"
You are asking the person if they are completely certain that what they think or said is true.
"Are you completely sure about that?"
(Completely - this word has the meaning of totally like you completely cleaned your room, everything is now clean.)
To be completely sure you have the greatest confidence that what you said is true and right.
例文：
"Do you really believe that?"
（本当にそう信じている？）
思っていることや言ったことが正しいと完全に確信しているのか相手に尋ねています。
例文：
"Are you completely sure about that?"
（本当に心からそう思っている？）
Completely という言葉は完全にという意味があり、例えばcompletely cleaned your roomと言えば部屋のすべてが綺麗になっていると意味します。
To be completely sure という表現ではあなたが自分の言ったことが正しいと多大な自信を持っていることを伝えています。
Do you feel like that from the bottom of your heart?
Are you completely sure about that?
When asking if someone really thinks something you can ask if they are 'completely sure' or 'definate'
you could also ask 'from the bottom of your heart' meaning something you really mean and are certain about
相手が本当にそう考えているのか確認したいときは、
'Are you completely sure about that?'（それは確かなことですか）
あるいは、
'Are you definate about that?'（それは確かなことですか）
と聞けます。
他に、'from the bottom of your heart' も使えます。これは、心の底から確信している事を表します。
Do you really believe that - from the bottom of your heart?
Do you sincerely believe that?
With the above two example sentences, the first one includes the tag: '..from the bottom of your heart'. Such language seems a little extreme in most day-to-day situations. However, it may be appropriate in a highly emotional situation, or where there is a disagreement about a morally correct attitude, perhaps, or where the speaker has doubts about the other person's sincerity.
一つ目の例文には末尾に '..from the bottom of your heart' というフレーズがあります。このような言い方は日常会話のほとんどの場面において少し大げさに聞こえます。しかし、例えば非常に感情的になっているときや、何が道徳的に正しいかについて意見が合わないとき、あるいは話し手が相手の誠実さに疑いを持っているときなどには、適切です。
Do you really think so?
Tell me the truth, what do you REALLY think?
It's just me, tell what you really think.
I need to hear the whole truth and nothing but the truth.
Swear you will tell me the whole truth.
Don't tell me anything but the truth.
I really appreciate your opinion so please be honest.
Do you really think so?（本当にそう思っている？）
Tell me the truth, what do you REALLY think?（正直に言って。本当にそう思っている？）
It's just me, tell what you really think.（私しかいないから言って。本当はどう思っているの？）
I need to hear the whole truth and nothing but the truth.（本当のことが聞きたいの）
Swear you will tell me the whole truth.（本当のことを言うって誓って）
Don't tell me anything but the truth.（本当のことしか言わないで）
I really appreciate your opinion so please be honest.（本当にあなたの意見は貴重だから正直に言ってね）
Do you think that?' Is simply asking for someone's thoughts. By adding 'do you really think that?', you are asking them if that is what they truly think. 'Truly' simply means truthfully. Another way to ask this is asking if that is what they 'truly believe'. 'Believe' is just another way of saying 'accept that it is true'.
Do you think that?' は単純に人の考えを尋ねます。
'Do you really think that?' は、それがその人の本当に考えていることなのかを尋ねます。
'Truly' は「本当に」という意味です。'Believe' を使って尋ねることもできます（→例2）。'Believe' は「事実だと受け入れる」という意味です。
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