Relative pronoun...

Today, I had an English grammar class. We studied relative pronoun. The main relative pronoun is who, what, whose, whom, which, that...and so on. We studied relative pronoun and had to some easy sentence like this.

For example...
I have a friend who speaks French very well.
I know a boy whose name is Takeshi.
I know a lady whom I met yesterday.

I wrote three sentences on the paper. Mr. Kamimoto checked my answer, and he said. "These sentences are Okay, but uninteresting sentences. " I noticed these sentences were too simple. when I or everyone write these sentences, we have to enjoy:)
I decided to write in English more interesting. Thank you Mr. Kamimoto:) I want to write in English better step by step!!