Direct speech consists of the exact words a person says or thinks. Indirect speech reports what someone has said or thought. In indirect speech, the tense of the verb depends on both the tense of the verb in the main clause (the verb of saying, thinking, promising, etc) and the tense of the verb in the words actually used by the person doing the speaking, thinking, promising, etc.
The conditional tense is used to describe what would happen in the future if something else happened first, or what would be possible or true if something else existed or was true. The conditional continuous tense is used instead of the conditional tense in order to emphasize that what is being described is a continuing state or action. The perfect conditional tense is used to say what would have happened in the past if something else had happened first or what would have been true if something else had been true. Like the conditional continuous tense, the perfect conditional continuous tense is used to emphasize that what is being described is a continuing state or action.
The future tense in English is formed with will or, less commonly, shall, plus a bare infinitive. The future continuous tense is often used to describe something that will happen in the future over a period of time rather than as a single action or event. It is also used to describe things that have been planned or things that can be expected to happen because they normally do, in which case it may refer either to continuous actions or to single actions.
The simple past tense is used to describe things that happened in the past or things that were true in the past. The things that happened in the past may be single, repeated or habitual actions. The simple past tense always describes events that have been carried out or completed in the past. The past continuous tense is used to describe actions in the past that continue for some time and do not have a stated or known beginning or end. For example, it is used in descriptions of the background situation, of what was going on, when some other action or event took place.
The simple present tense is used to talk about facts or things that are generally true. The simple present tense is also used to talk about repeated actions. The present continuous tense is used to talk about something that is happening at or round about the time of speaking or about situations that will only last for a limited period of time. The simple present tense with always denotes something that happens every time. The present continuous tense is used with always to refer to something that happens very often, but not necessarily every time, and generally suggests that the speaker is annoyed about it or thinks it is unnecessary or unreasonable.
The tense of a verb shows whether the action of the verb happens in the past, the present or the future, whether it is a single action or a repeated action, whether the action is completed or unfinished, and so on. There are sixteen tenses in English. They will be separated into four groups, and studied in four topic.