A sentence written using only hiragana is the most difficult to read.
Japanese people find it hardest to read a sentence written in only hirigana.
Pure hiragana is hard to read.
"a sentences using only (something)" - this means a sentence that only contains (something)
"pure" means only or wholly
A. What is the most difficult script for Japanese people to read, in your opinion.
B. I would say pure hiragana.
A. Really?
B. Yes, a sentence written using only hiragana is the most difficult to read.
"a sentences using only (something)"
（～ばかりの文章）
- これは（何か）ばかりを含んだ文章と言う、意味になります。
"pure"とは純粋な何も他のものが含まれていない、と言う意味です。
【例文】
A. What is the most difficult script for Japanese people to read, in your opinion.
（日本人にとって一番読みずらい原稿って何ですか？あなたの意見で）
B. I wouldｇ say pure hiragana.
（平仮名だけで書かれているものでしょうかね）
A. Really?
（ホントに？）
B. Yes, a sentence written using only hiragana is the most difficult to read.
（はい、平仮名だけで書かれているものが一番読みずらいです）
It is harder for me/us/Japanese people to read when it is written in Hiragana.
It is more difficult for me to read when it is written in Hiragana.
"It is harder for me/us/Japanese people to read when it is written in Hiragana."
Harder means it is more difficult.
"Me" refers to you.
Us refers to a group of people.
Japanese people refers to the name of the group.
This sentence explains that when the paragraph you are reading is written in characters it is harder or more difficult for you to read than when it is written in words.
"It is harder for me/us/Japanese people to read when it is written in Hiragana."
（私/私たち/日本人にとって、平仮名で書かれているのを読むのはさらに難しい。）
Harderは、「さらに難しい」という意味です。
Meは、「あなた」のことを指しています。
Usは、（あなたを含む）複数の人々を指します。
Japanese peopleは、複数の人々の名前を指します。
こちらの文は、あなたが読んでいる文章が、漢字を使って書かれているよりも、平仮名で書かれているほうが、読むのが難しいということを説明しています。
Japanese people may find a piece written in all hiragana text more awkward than reading hiragana mixed with katakana and kanji, as normal.
Awkward - causing difficulty; hard to do or deal with.
"She was asking some awkward questions"
synonyms: difficult, tricky, fiddly
"One of the most awkward jobs is painting a ceiling."
People may get used to reading the more usual combination of hiragana mixed with katakana and kanji, To be faced suddenly with having to read only hiragana may require some extra concentration.
Awkward - 困難を招く、扱いにくい
例
"She was asking some awkward questions"
（彼女は厄介な質問をしていた。）
同義語: difficult, tricky, fiddly
例
"One of the most awkward jobs is painting a ceiling."
（もっともやりにくい仕事のひとつは、天井を塗ることだ。）
人々は、カタカナや漢字と、平仮名が混じったものを読むのに慣れているので、いきなり平仮名だけのものを読まなければいけなくなると、さらに集中力が必要です。
Sentences written in all hiragana are actually harder to read for Japanese.
It's actually harder to read sentences that are only written in hiragana.
Kanji actually makes it easier to read, because you can see each word!
The third one is good if you want to explain why only reading hiragana is difficult. If it is all hiragana, it's hard to separate each word in your mind.
A Japanese speaker usually finds it more difficult to read a sentence written in just hiragana than in katakana or kanji.
For a Japanese person, it can be more difficult to read a sentence written in all hiragana than a normal sentence.
Hiragana sentences are the most confusing for a Japanese speaker.
I chose the word, "difficult" for the first two sentences and, "confusing" for the third, but the basic meaning is the same. Something is difficult to read when it causes confusing or leaves the reader uncertain about its meaning, or when it produces a struggle in order to understand it clearly.
最初の二つの文には "difficult"、三つ目の文には "confusing" という単語を使いましたが、基本的な意味は同じです。
"difficult to read"（読むのが難しい）は、読み手を混乱させる（confusing）もの、意味が分かりにくいもの、あるいは理解するのが大変なものをいいます。
Hiragana sentences can be harder to read than normal ones
If something is not easy to do it is said to be 'hard to' so by saying 'harder to read' it means it is not as easy to read.
Harder means it more hard than something else so it's harder to read than normal sentences
hard to' は「～するのが難しい」という意味です。ですから、'harder to read' で「読むのがより難しい」となります。
'harder' は「～より難しい」という意味です。普通の文章よりも読むのが難しい、ということです。
It is troublesome for Japanese people to read sentences composed in hiragana.
Writing that is entirely composed in hiragana is extremely difficult to read.
Absolute hiragana is challenging to read.
When something is "troublesome" it causes difficulty and annoyance so saying "It is troublesome for Japanese people to read sentences composed in hiragana." is a perfect way to describe difficulty and inconvenience.
Using "entirely" in a sentence describes to be completely done in a specific way. Therefore "Writing that is entirely composed in hiragana is extremely difficult to read." can also describe the sentence in a natural way.
Absolute means total so saying "Absolute hiragana is challenging to read." describes that anything that is written solely in hiragana is difficult to read.
"troublesome" とは、難しくて面倒なことをいいます。ですから、"It is troublesome for Japanese people to read sentences composed in hiragana."（ひらがなで書かれた文章は日本人にとっては厄介です）は、難しさと不便さを表すパーフェクトな言い方です。
"entirely" は「完全に」という意味です。ですから、"Writing that is entirely composed in hiragana is extremely difficult to read."（ひらがなだけで書かれた文はものすごく読みにくいです）これも自然な言い方です。
"absolute" は「完全な」という意味です。ですから、"Absolute hiragana is challenging to read."（ひらがなだけだと読みにくいです）は「ひらがなだけで書かれたものは読みにくい」という意味です。
Sentences written purely in hiragana are the most difficult to read.
Japanese people find it more difficult to read a sentence written only in hiragana.
To explain that a sentence written in all hiragana can be harder to read than normal sentences with hiragana/katakana/kanji, you can say:
"Sentences written purely in hiragana are the most difficult to read."
"Japanese people find it more difficult to read a sentence written only in hiragana."
「平仮名だけで書かれた文は漢字やカタカナも使った文に比べ読みにくい」と説明したいなら、次のように言えます。
"Sentences written purely in hiragana are the most difficult to read."（平仮名だけで書かれた文は一番読みにくい）
"Japanese people find it more difficult to read a sentence written only in hiragana."（平仮名だけで書かれた文は日本人にとっては読みにくい）
アメリカ合衆国 
南アフリカ 
イギリス 
