Even people who can't speak English wasere able to teach grammar and simple sentences.

One of my students appeared to grow up in a deprived environment.

I was terribly sorry for earningreceiving money from his single mother.

We don't usually use "to earn" in this way.

However, I was also disgusted that the son was unwilling to study diligently.

Alternative:¶
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Though I know that most things learned at school are useless in daily life, I guess that being good at studying something is essential toin developing one's career.

Fortunately, mMost Japanese people aren't good at English, a. Acquiring an English test certification isn't easy but, fortunately, an effective way to get a job.

We put "fortunately" right before the positive benefit.

Skills which require a lot of efforts are great advantages.

We rarely use the word "effort" as a plural noun. I think it's because it's an abstract noun.

Even people who caouldn't speak English wasere able to tleachrn grammar and simple sentences.

One of my students appeared to have grown up in deprived environment.

Fortunately, most Japanese people aren't good at English, a. Acquiring English test certification isn't easy but it is an effective way to get a job.

Skills whichthat require a lot of efforts are a great advantage.