English Grammar A1 Level: A modal verb is a type of auxiliary (helping) verb  that has no meaning on its own but it modifies the main verb, changes  its meaning and gives more details about the action.

The verb can is a modal verb  used to express the idea of ability or opportunity, to express the  possibility or impossibility of an event or action happening and to ask  for or give permission.

https://open.books4languages.com/english-a1-grammar/chapter/can-modals-of-ability

English Grammar A1 Level: We use the verb to have to form common expressions in informal communication.

https://open.books4languages.com/english-a1-grammar/chapter/to-have-common-expressions

English Grammar A1 Level: Have/have got is a verb used to express states like possessions, relationships, illnesses and characteristics of people and things.

When expressed in its interrogative form, it is used to ask questions about the possession of something.

https://open.books4languages.com/english-a1-grammar/chapter/have-and-have-got-interrogative

English Grammar A1 Level: Have/have got is a verb used to express states like possession, relationship, illnesses and the characteristics of people and things.

When expressed in its negative form, the verb denies something about the subject.

https://open.books4languages.com/english-a1-grammar/chapter/have-and-have-got-negative

English Grammar A1 Level: Have/have got is a verb used to express states like possession, relationship, illnesses and the characteristics of people and things.

When expressed in its affirmative form, the verb confirms something about the subject.

https://open.books4languages.com/english-a1-grammar/chapter/have-and-have-got-affirmative

English Grammar A1 Level: Articles are words that define nouns and they belong to the group of words called determiners. Essentially there are two kinds of articles: indefinite and definite.

We use the definite article to refer to specific things.

https://open.books4languages.com/english-a1-grammar/chapter/definite-articles

English Grammar A1 Level: Articles are words that define nouns and they belong to the group of words called determiners. Essentially there are two kinds of articles: indefinite and definite.

We use indefinite articles to express non-specific things or general categories.

https://open.books4languages.com/english-a1-grammar/chapter/indefinite-articles

English Grammar A1 Level: Determiners are modifiers of nouns. They can provide information about which and how much/many people, things… we are talking about.

Quantitative determiners or quantifiers are used to indicate the quantity of something.

https://open.books4languages.com/english-a1-grammar/chapter/quantitative-determiners

English Grammar A1 Level: There is/are are expressions used in sentences that want to confirm, deny or check that something exists.

https://open.books4languages.com/english-a1-grammar/chapter/there-is-and-there-are

English Grammar A1 Level: Nouns refer to a person, place, thing, event, substance or quality.

Countable nouns are nouns considered as separate objects that can be counted with numbers.

Uncountable nouns refer to things we consider as a mass, and not as separate objects.

https://open.books4languages.com/english-a1-grammar/chapter/countable-and-uncountable-nouns