REFERENCE

Consists of the substitution of words or groups of words by others, with the purpose of avoiding the repetition. They generlly are PRONOUNS.

EXAMPLE:

In the afternoon Mary was walking in the park when Mary saw that two children were running in the park, Mary was very happy because the children were with their family and the children were happy.

WE USE THE PRONOUNS TO AVOID THE REPETITION OF THE NAMES

In the afternoon Mary was walking in the park when SHE saw that two children were running in the park, SHE was very happy because THEY were with their family and the THEY were happy.