Let's improve our writing skills. Relative pronouns and adverbs for linking ideas

Relative pronouns and adverbs are often used  for linking ideas. Look at these examples:

I’m staying in  a comfortable hotel, which/ that was recommended me by Nick .
Nick is my close friend, who/ that often travels arount the world

So, he is a person whose recommendations are always so helpful.

The main relative pronouns are: who, whom, whose, that, and which. 

Relative adverbs are: when, where, and why. 

These words  act as a link between two parts of a sentence.
We use 

•    Who/ that           to refer to  people.
•    Which/that         to refer to objects or animals.
•    Whose                for people to show possession .
•    When                  to refer to  time
•    Where                 to refer to  place
•    Why                    to give  reason.  

                  
Besides adding detail, such sentences can be useful stylistically. When used properly, they allow you to combine connected ideas in the same sentence. That is one more way to  demonstrate your level of English.
Consider the difference between the following sentences:

I’m staying in  a comfortable hotel. It was recommended me by Nick .
I’m staying in  a comfortable hotel, which was recommended me by Nick .

Both sentences communicate the same thing, but the second does a better job of connecting the two events.

As you can see, relative clauses must be used in your compositions. But, you shouldn’t use too many of them at once. Sentences will be confusing to your reader if they have clauses that are too numerous or too long.