1. Grammar is the study of the rules and principles that govern and regulate the use of languages and how words should be organized within a sentence. But at the same time, grammar is in fact the set of rules and principles that govern the use of a given language, because each language has its own rules and principles.
2. The main approaches to the study of grammar are as follows:
2.1. Descriptive grammar. Unlike the previous one, it does not judge as "correct" or "incorrect" the way in which different speakers use the language, but aims to understand how the language rules are actually used within a given community or communities.
2.1.1. Examples: You don't go that way, it's dangerous I'll see you tomorrow Not around the house, I'm too tired
2.2. Prescriptive grammar. As its name indicates, it starts from an ideal and a sense of what is correct in the language, to suggest to its speakers the appropriate or recommendable way to formulate and organize their sentences.
2.2.1. Examples: Don't go that way, it's very dangerous in that area. Maybe I can see you tomorrow Not around the house, I feel very tired.
3. Definite Article If you are talking about a definite thing, person, place, idea or a noun you have mentioned before, you use the definite article “the” no matter the number, just the fact that it was mentioned before, or the receptor already knows what you are talking about.
3.1. Singular
3.1.1. Do you remenber the first gift you gaves me?
3.1.2. The cell phone I bought is amazing.
3.1.3. I want The brown purse.
3.2. Plural
3.2.1. I did not see The flowers on the table.
3.2.2. The big bicycles are dangerous
3.2.3. The funny teachers are the best
4. Singular and Plural Nouns.
4.1. Singular Nouns. A singular noun is the noun to name one person, place, thing, or idea.
4.1.1. Fan Example: My mother´s fan broke down.
4.1.2. Vet Example: You must take the cat to a Vet.
4.1.3. Play ground Example: The Smith`s playground is huge.
4.1.4. Idea Example: Rebeca´s idea was amazing.
4.2. A plural noun is the noun to name more than one person, place, thing or idea.
4.2.1. Decisions Example: Women´s decisions are well planned
4.2.2. Kids Example: Your kids are adorable
4.2.3. Cities Example: Ely´s dream is to visit the best cities in the world
4.2.4. Pictures Example: All the pictures got damaged