猿も木から落ちる Even Monkeys fall from Trees

The example sentence (not to be taken too seriously), is more for intermediates:

猿も木から落ちるというけど、あんなに賢い国語の先生が、「一」という字を間違えたな んて信じられない。
saru mo ki kara ochiru to iu kedo, anna ni kashikoi kokugo no sensei ga, ichi to iu ji o machigaeta nante shijirarenai
As they say, “Even monkeys fall from trees,” but for such a brilliant Japanese teacher to mess up such a character is hard to believe.

猿も saru mo – Even a Monkey
木から ki kara – from a tree
落ちる ochiru – to fall
という to iu – is like a quotation marker
けど kedo – but
あんなに annani– for such a
賢い kashikoi – wise; bright; clever
国語の先生 kokugo no sensei – teacher of Japanese
一 ichi – one; indisputably the easiest of all kanji
という to iu – is like a quotation marker
字 ji – character; here meaning Chinese characters
間違えた machigaeta -　made a mistake
なんて nante -　such as but with a negative emphasis
信じられない shinjirarenai – I can’t believe it