We use 'rather' in this context to mean 'a little', 'a bit', or 'a tad'. All these words are interchangeable. However, the most commonly used in this context are 'a little' and 'a bit'. If you are talking to a native speaker, saying "it was rather difficult"or "it was a tad difficult" will be immediately understood. However, if you are talking to a non native speaker, it would be advisable to use the more common 'a little' or 'a bit'.
So, you may say:
It was rather difficult.
or
It was a little difficult.
or
It was a bit difficult.
この場合の'rather'は、'a little'や'a bit'、'a tad'（[少し](https://eikaiwa.dmm.com/uknow/questions/34614/)）という意味です。これらは全て置き換え可能です。しかし、この文脈では'a little'か'a bit'を使うのが一般的です。
ネイティブスピーカーと話しているなら、"it was rather difficult"や"it was a tad difficult"はすぐに理解してもらえるでしょう。しかし、ネイティブでない人と話しているなら、より一般的な'a little'または'a bit'を使うことをお勧めします。
It was rather difficult.
少し[難しかった](https://eikaiwa.dmm.com/uknow/questions/36244/)。
It was a little difficult.
少し難しかった。
It was a bit difficult.
少し難しかった。
The three sentences you see provided above are great ways to express to your listener that a question was only slightly difficult. In the first sentence you will see the word a bit, in the second sentence you will see the word a tad bit and in the third sentence you will see the word a little bit. All the words mean slightly or somewhat. These three words are common in our everyday conversation and they would make great additions to your vocabulary.
上記は3例とも、問題が少しだけ難しかったことを表す言い方です。
最初の例文では"a bit"、二番目の例文では"a tad bit"、そして三番目の例文では"a little bit"という言葉を目にすると思います。これらはすべて「少し、ちょっと」という意味です。三つとも日常会話でよく使われますので、語彙に加えておくといいと思います。
It was a bit difficult
It was a little difficult
It was a little hard
It was a bit hard
It was harder than I expected
It was a bit difficult
少し難しかった。
It was a little difficult
少し難しかった。
It was a little hard
少し難しかった。
It was a bit hard
少し難しかった。
It was harder than I expected
思っていたより難しかった。
"Just a little" is really a commonly used phrase. "Do you speak English?" "Just a little" is always a safe answer. "Was the exam difficult?" "Just a little difficult". When something is difficult or hard we have no problem expressing the amount of difficulty with just one simple word. But if we would like to express only a little bit difficult, it's enough to put "little", "a bit" or "lightly" before the word "hard" or "difficult". For a more formal level of difficulty, like in science and technology, sometimes we are asked, "what was the level of difficulty?" and we can respond "There was a low level of difficulty in the making of the project" or "there was a small amount of difficulty in the running course."
"Just a little" （ちょっとだけ）は本当によく使われるフレーズです。
"Do you speak English?"（英語を話しますか？）に対して、"Just a little"（ちょっとだけ）というのは、無難な返答でしょう。
"Was the exam difficult?"（試験は難しかった？） "Just a little difficult"（少しだけ難しかった）
何かが難しい（difficult/hard）場合には、一言で表せます。少しだけ難しいと言いたいなら、 "hard"や"difficult"の前に"little"、"a bit"または"lightly" を付けます。
科学やテクノロジーなどよりフォーマルな「難しさ」の場合には、"What was the level of difficulty?"（どれくらい難しかったですか？）と聞かれることがあります。それに対しては、"There was a low level of difficulty in the making of the project"（プロジェクトはそれほど難しくありません。）や "There was a small amount of difficulty in the running course."（そのコースは少し難しかった。）
まず少しは"Kind of"という意味です。
"It was kind of difficult"
気に入ったら距離感が近い場合の説明：
普段に"It was kind of difficult"を発言するけど、仲がいい人と話す場合"kind of" を略して"kinda'"となります。
つまりタメ口で"It was kinda' difficult" となります。
In English we have many words for "a little bit" of something . The most common ways we can say this phrase is: a little bit, sort of, kind of, slightly , more or less, a small part was , some, quite , small amount. Now if you want to be specific about which part was a little bit difficult you could say "within reason" or "it was easy for the most part" . When describing "a little", you can be very vague or you can be specific. When using these examples in business be careful not to be too informal .
英語には「少し」を表す表現が沢山あります。
最も一般的に使う表現は、次の通りです。
【少しの例】
a little bit
sort of
kind of
slightly
more or less
a small part
some
quite
small amount
そして、どこの部分が少し難しかったのか詳細に述べたいなら、例えば次のように言えます：
"within reason" (無理でない範囲）
"it was easy for the most part"（ほとんどの部分は簡単でした）
「少し」は曖昧に表すこともできますし、具体的に表すこともできます。これらの例をビジネスで使う場合には、インフォーマルになりすぎないように気をつけてください。
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