"I didn't think it was such a hard job. "
「こんなに、大変な仕事だとは思わなかったよ。」"hard job"というのは「大変な仕事」という意味を持っています。あと、"to think"は「思う」に相当します。
"I didn't imagine this job to be so difficult."
「この仕事がそんなに大変だとは想像しかったよ。」"hard"の代わりに、同じ意味を持っている"difficult"を使った文です。"to imagine"は「想像する」という意味です。
参考になれば幸いです。
When we 'do not expect' something this means that we thought that the activity or in this example the job, would have been different from our initial expectations.
Another example using this phrase could be "I did not expect the new Star Wars film to be so good, but it was amazing."
Both of these answers have the same basic meaning as "I didn't think the job would be so hard."
「do not expect」は、活動（この例では仕事）が最初思ったのと違ったことを表します。
この言い回しを使った別の例文は：
I did not expect the new Star Wars film to be so good, but it was amazing.
（新しいスター･ウォーズの映画はあまり期待していなかったのですが、素晴らしかったです。）
どちらの例文も基本的には「I didn't think the job would be so hard（その仕事がそんなに大変だとは思っていなかった）」という意味です。
"More than I bargained for" is an expression that means something required more than was planned.
Another way to phrase this is to compare how easy the job is to your expectations.
"Tough" is a word that means difficult.
"More than I bargained for" は「予想以上のことを求められる」の意味です。
他に、「もっと楽だと思っていた」という言い方もできます（例2）。
"Tough" は「難しい」という意味の語です。
My new job's a little more challenging than I imagined
I thought the grass would be greener - but it isn't
Well, context is always important and your personal situation at the time of starting a new job will dictate the language you use. For example, you may be happy with your new job generally, but some aspects are quite difficult. However you may be enjoying the new challenges. The first example sentence might reflect that attitude. The second example sentence indicates you are unhappy with your new job and wish you had stayed in your last position.
Proverb: 'The grass is always greener on the other side.'
そうですね。文脈が常に重要で、あなたが新しい仕事を始めるときの個人的な状況によって言い方が変わります。例えば、新しい仕事に大体は満足しているが、少し難しい部分もある。ただ、あなたは新しい挑戦を楽しんでいる。最初の例文でこの気持ちが表せるかもしれません。
2文目では、新しい仕事に満足しておらず、前の仕事にいれば良かったと思っています。
ことわざ：The grass is always greener on the other side.（隣の芝生は青い。）
if you think about something you can also say you thought or realised so as well as saying 'I didn't think' or 'I didn't realise'
you can use both the words 'hard' or 'difficult' to explain something is not easy
Realize' used other than 'think' or 'believe' something, in this case they didn't realize or think that the job would be as hard as it is.
"This job isn't as easy as I thought" 'easy as I thought' a term causally used in western cultures when describing something difficult.
think' や 'believe' 以外に 'realize' も使われます。この場合は、「仕事がこんなに大変とは思わなかった」ということ。
"This job isn't as easy as I thought"（この仕事は思ったほど簡単ではない）
'easy as I thought' は「難しい事」を表すときに欧米の文化で使われるカジュアルな表現です。
"I wasn't expecting this job to be so hard."
"This job is harder than I thought."
Both expressions are very popular to use. These expressions let people know that you were not expecting the job to be hard. Maybe the description was misleading or when you interviewed some details were left out so you go ahead say one of the two expressions above.
"I wasn't expecting this job to be so hard."（この仕事がこんなに大変だとは思わなかった）
"This job is harder than I thought."（この仕事は思っていたよりも大変です）
どちらもよく使われる表現です、「大変な仕事とは思っていなかった」と伝えています。
仕事の説明が誤解を与えるものだったとか、あるいは面接のときには伝えられていなかったことがあったということかもしれませんね。上記の表現を使ってみてください。
Having expectations always makes us think that things will turn out almost exactly how we hope.
When we get a new job we have high hopes that the job will be satisfactory and that we will not have to slave away.
The sentences above state that this new job was not expected to be so difficult but is now causing strain.
ご質問ありがとうございます。
・「I didn't think this job would be so hard. 」
（意味)こんなに大変な仕事だとは思わなかったよ。
<例文>I didn't think this job would be so hard. I'm stressed every day and I have no time to rest.
<訳>こんなに大変な仕事だとは思わなかったよ。毎日ストレスを感じていて、休む時間もありません。
ご参考になれば幸いです。
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