The Simple Tenses
The simple tenses are used to show permanent characteristics of people and events or what happens regularly, habitually or in a single completed action.
Present Simple Tense
The simple present is used to describe an action, an event or condition that is occurring in the present, at the moment of speaking or writing. The simple present is used when the precise beginning or ending of a present action, event or condition is unknown or is unimportant to the meaning of the sentence.
The PRESENT TENSE uses the verb's base form (write, work), or, for third-person singular subjects, the base form plus an -s ending (he writes, she works).
Past Simple Tense
The simple past or past simple, sometimes called the preterite, is the basic form of the past tense in Modern English. It is used principally to describe events in the past, although it also has some other uses.
Simple Future Tense
In English, there are many ways of talking about events in the future. Many students find it difficult to decide which form to use in a particular situation. In this video, it is explained the differences between four main forms which are used to express future time.