のはむずかしい

it is difficult to

→ の
phrase Rare #26,348
it is difficult to The の nominalizes the preceding verb or clause, making it the subject of むずかしい (difficult). Often translated as “doing ... is difficult.”
JA: 一人でこの問題を解くのはむずかしい。
EN: It is difficult to solve this problem alone.

フランス語を学ぶのはむずかしい

Learning French is difficult.

東京では広いアパートなど手に入れるのはむずかしいのです

It’s difficult to find a spacious apartment in Tokyo.

彼がその問題を解決するのはむずかしい

It is difficult for him to solve that problem.

ラッシュの時にこのあたりでタクシーを捕まえるのはむずかしい

It’s difficult to catch a taxi around here during rush hour.

彼女に会うのはむずかしいわかるだろう

You’ll realize that it’s difficult to meet her.

どちらの車がよいか言うのはむずかしい

It's difficult to say which car is better.