This document discusses conditionals and tenses in English grammar. It explains that conditionals are used to talk about possibilities and hypothetical situations, often using the word "if". There are several types of conditional sentences that use different verb tenses, including the zero conditional which uses present tense, the first conditional using present and future, the second using past and conditional, and the third using past perfect and conditional. The document also discusses how tense is used to refer to timeframes like past, present and future, and aspects like completed or ongoing actions.

1. Conditionals in grammar use.

2. A verb-based technique used to show the time, and
sometimes the persistence or completeness, of an act
or state in relation to the time of verbal
communication.
The model of tense in English is a system that we
use to refer to time - past, present and future.
Many languages exercise tense to talk about time.
Other languages have no perception of tense at all,
but of course they can still talk about time, using
diverse methods.

3.  Verbs come in three tenses: past, present, future.
 The past is used to describe things that have already
happened. The present tense is used to describe things that
are happening right now, or things that are continuous.
The future tense describes things that have yet to happen.
 We cannot talk of tenses without bearing in mind two
components of many English tenses: time and aspect. In
simple terms
Time expresses:
 Past - before now
 Present - now, or any time that includes now
 Future - after now
Aspect can be:
 Progressive - uncompleted action
 Perfective - completed action or state

4.  Conditional tenses are used to contemplate about
what might happen, what might have happened,
and what we wish would occur. In English, most
sentences using the conditional contain the
word “if”.
 Many conditional forms in English are used in
sentences that include verbs in one of the past
tenses.
 This is referred to as "the unreal past" because
we use past tense but we are not referring to
something that happened in the past.

5.  The Zero Conditional:
(if + present simple, present simple)
If you heat water to 100 degrees, it boils.
 The First Conditional:
(if + present simple, will + infinitive)
If it rains tomorrow, we'll go to the cinema.
 The Second Conditional:
(if + past simple, would + infinitive)
If I had a lot of money, I would travel around the world.
 The Third Conditional:
(if + past perfect, would + have + past participle)
If I had gone to bed early, I would have caught the train.