Pronoun - is the part of speech that takes the place of or substitutes a noun.
It is good that pronouns had been invented because if not, writing and speaking will be so boring if we are going to hear and read the same names (in writing, it's troublesome to write long names too!) over and over again. Imagine your essay for example about the "mysterious woman in black dress" - the name is unknown. You have to write that name phrase you called her again and again to say something about her, without using Pronouns, it would be difficult, I suppose. Thanks it has came about :)
The "basics" about PRONOUNS...
The "basics" about PRONOUNS...