Confusion of Tens - Interesting

Do we have 'three tenses' or 'two tenses' in English? 

First, the straightforward answer is: we have only two 'tenses' in English, and they are:
1. The past tense
2. The present tense

e.g. I learned English.
(Past tense)

e.g. I learn English.
(Present tense)

For reference, check David Crystal's book called "The Cambridge Encyclopedia of the English Language".

Therefore, we have no 'Future tense'.

Second, Before explaining how and why we have two tenses in English, let's first understand the 'tense' itself.

"Tense"
Origin of "TENSE"
The word "Tense " is derived from the given words:
1. Latin word: Tempus
2. Greek word: Tensus
3. Old French word: Tens
4. Modern French word: Tense

They all mean "TIME"or "ERA"

Definition:
Tense is a grammatical word which indicates the "time of an action" or situations in the PAST and PRESENT. Therefore, the modification of a VERB is called TENSE to indicate the TIME of the action or STATE.

What is time?
'Time' is a universal concept consisting of three 'divisions':
1. Past
2. Present
3. Future

Third, since we have already said that we have 'two' tenses which are 'past' and present', then we can also say that we have two kinds of verbs 'past' and 'present', but notice that main verbs have six forms in English as below:
1. Break = base form
2. Break = general present
3. Breaks = third person singular
4. Broke = past
5. Breaking = present participle
6. Broken = past participle

And, consequently, these six forms of verbs refer either to present time or to past time.

Fourth, a question:
How can we say that we don't have 'future tense'?

Answer:
English has no future tense at all, BUT we form or indicate 'future' tense or 'aspect' with specific auxiliary verbs, i.e. Will, with the help of 'present' tense.

Each tense is divided into four subcategories:
A) Past:
1. Simple past
2. Past progressive
3. Past perfect
4. Past perfect progressive

B) present:
1. Simple present
2. Present progressive
3. Present perfect
4. Present perfect progressive

C) future:
1. Simple future
2. Future progressive
3. Future perfect
4. Future perfect progressive

Note that some modern grammarians say that English tenses are divided into 16 subcategories.

And, at last, we can conclude that we have:
Two tenses:
1. The past tense
2. The present tense

Four aspects:
1. Simple
2. Perfect
3. Progressive
4. Perfect progressive

Two voices:
1. Active voice
2. Passive voice

Five moods:
1. Indicative mood
2. Interrogative mood
3. Imperative mood
4. Subjunctive mood
5. Infinitive mood