INTRODUCTION

Currently, English is an important part of the educational process. Throughout the 20th century, English has progressively become the most spoken language in the world and is considered the main element of communication between very diverse cultures and allows access to greater knowledge and information and to be updated with the rest of the cultures.

English will provide access to a better education and therefore the possibility of obtaining better job opportunities which will multiply in terms of the level of proficiency in the language. Speaking English is an important tool for personal development. In this aspect, studies carried out in the last years have found that learning a language favors a better brain development, improving memory, concentration capacity and multitasking skills. Learning a language is learning about another culture. This is another of the most outstanding advantages of knowing English because it helps understanding, acceptance and respect for the diversity of the world.

In English, most sentences that employ the conditional verb tense contain the term "if". Many English conditional constructions are used in sentences that include verbs in the past tense. This usage is called "the unreal past" because we are using a past tense, but we are not referring to something that actually happened. There are four main ways of constructing conditional sentences in English. These are used to speculate about what might happen, what might have happened, and what we wish would happen.

Students to know these topics should have a basic knowledge of the present simple, rules of the present simple in third persons, past simple, know the rules that apply to regular and irregular verbs, past with irregular verbs, modal would and will, present perfect and modal would in present perfect.

English has been positioned as a universal language that crosses countless borders. The vision of the British Empire was to establish English as a language that could connect multitudes worldwide, connect people and position this language globally, making it possible for large masses of people to interact without the necessity of knowing each other's linguistic origins.

Zero conditional

The "zero conditional" is used when the time we refer to is now or always and the situation is real and possible. This type of conditional is usually used to talk about general facts. The verb tense of both propositions is the "simple present". In type 0 conditional sentences, the term "if" can usually be replaced by "when" without changing the meaning.

Type 1 conditional

The "type 1 conditional" is used to refer to the present or future when the situation is real. The type 1 conditional refers to a possible condition and its probable result. In these sentences, the "if" clause adopts the "simple present" and the main proposition the "simple future".

Type 2 conditional

The "type 2 conditional" is used to refer to a time that can be now or at any time and to a situation that is not real. These sentences do not refer to facts. The type 2 conditional is used to refer to a hypothetical condition and its probable outcome. In these sentences, the "if" proposition adopts the "simple past" and the main clause the "present conditional".

Type 3 conditional

The "type 3 conditional" is used to refer to a time situated in the past and to a situation contrary to reality. It is based on facts that are the opposite of what is being expressed. The type 3 conditional is used to refer to a condition in the past that is not real, as well as to its probable result in the past. In these sentences, the "if" clause adopts the "past perfect" and the main proposition the "perfect conditional".