It seems that he cannot understand the meaning of the question when it's written out in sentences.
He seems unable to get the meaning of the question itself.
ご質問ありがとうございます。
① "It seems that he cannot understanding the meaning of the question,"＝「彼には、質問の意味が理解できないようです、」
"when it's written out in sentences."＝「文章で書かれている場合は。」
② "He seems unable to get the meaning of the question itself."＝「質問そのものの意味が分からないようです。」
ご参考までに。
アメリカ合衆国 
