Learn more about Grammar:
Adjectives: An Easy Guide with ExamplesAdverbial Clauses: What Are They?AdverbsAnalogy: Definition & Meaning (with Examples)ArticlesBad AdverbsClauses: Definition, Meaning, and How to Use ThemConjunctionsCoordinating Conjunctions: What Are They and When Should You Use Them?Dangling ModifiersDeclarative Sentence: Examples + MeaningExaggerationHomophones: Definition and ExamplesHow to Use Subordinating ConjunctionsInfinitivesInterjections: Definition, Meaning, and ExamplesIntransitive Verb: Definition, Meaning, and ExamplesNounsParticiples PluralsPrepositional Phrase: What Is It & How to UsePrepositionsSplit Infinitive: The Complete Guide (with Examples)Subordinate Clause: Definition, Types, and ExamplesThe Complete Guide to Transitive VerbsTransitions: A Complete Guide (with 100+ Examples)Types of VerbsVerbsWhat is a Pronoun? Rules and ExamplesWhat Is Symbolism in Writing?Word ClassesHow are "pretty" and "quite" used?

Pretty and quite belong to a group of adjectives known as 'intensifiers'. These words are often used to create emphasis or indicate exactitude.
These intensifiers actually make your writing less clear.
For example:
- The ball is pretty round.
- The ball is round.
Here, the sentence with the intensifier pretty is less exact than the sentence without it.
In technical writing, you should avoid using intensifiers in your work.
If you're writing fiction, they can be used if your character speaks casually or in an opinionated manner. But even then, don't overdo it!