English grammar and pronunciation are too difficult.
Both English grammar and English pronunciation are difficult.
"English grammar and pronunciation are too difficult."
「英語は文法と発音が難しすぎる！」
「文法」は"grammar"で、「発音」は"pronunciation"といいます。
"too difficult"は「難しすぎる」に相当します。
"Both English grammar and English pronunciation are difficult."
「英語の文法も英語の発音も難しい！」
"Both A and B are..."は「AもBも○○」という意味を持っています。
参考になれば幸いです。
Grammar and pronunciation is the hardest part of learning English!
Most people that are learning English, they would all agree that grammar and pronunciation are the most difficult. Most of them would say that English has too many rules and that the spelling for most words are different from the way we say these words. Pronunciation is especially difficult when in your native language you don't use certain sounds that we have in English and this is part of the reason why it is difficult.
What is the hardest part of learning English?
"In my opinion, grammar and pronunciation is the hardest part of learning English!"
ほとんどの英語学習者が、文法と発音が最も難しいと感じると思います。「英語にはルールが多すぎる」とか「英単語はスペルと発音が違う」のように感じるのではないのでしょうか。
発音は、特に自分の母語にない音が英語にあると、難しくなります。
What is the hardest part of learning English?（英語学習において最も難しいところはどこですか）
"In my opinion, grammar and pronunciation is the hardest part of learning English!"（個人的には文法と発音が英語を学ぶ上で最も難しいと思います）
We use 'is' instead of 'are' because we are referring to grammar and pronunciation being one thing so it's IT IS also because both nouns are uncountable so they cannot be plural.
We can also say:
English grammar and pronunciation is difficult for me!
ここで 'is' ではなく 'are' が使われるのは、話し手が 'grammar'（文法）と 'pronunciation'（発音）を一つのものとして捉えている、そして、この二つの名詞が不可算名詞であることによります。
次のように言うこともできます。
English grammar and pronunciation is difficult for me!
（英語の文法と発音は難しい）
If something is not easy to then then it is said to be 'hard' or 'difficult' by keeping it simple it is a more casual way of saying it so you would simply say
'English grammar and pronunciation are hard/difficult!'
何かが簡単でないことは 'hard' または 'difficult' で表すことができます。
シンプルに表現することでカジュアルに伝えることができます。
ですから、
'English grammar and pronunciation are hard/difficult!'
（英語の文法と発音は難しい）
と言えます。
The hardest part about English is grammar and pronunciation.
I find grammar and pronunciation to be the most difficult part of learning English.
Grammar and pronunciation is definitely the hardest part of learning English.
You have to put a great deal of effort in understanding pronunciation and grammer in order to learn the English language.
I have difficulties in grammar and pronunciation when learning the English language.
You have to put a great deal of effort in understanding pronunciation and grammer in order to learn the English language.
（英語学習では発音と文法に多くの労力が必要になります）
I have difficulties in grammar and pronunciation when learning the English language.
（英語の文法と発音が苦手です）
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