Past tense

past tense (abbreviated pst) is a grammatical tense that places an action or situation in the past of the current moment (in an absolute tense system), or prior to some other event, whether that is past, present, or future (in a relative tense system).[1] Not all languages mark verbs for the past tense (Mandarin Chinese, for example, does not); in some languages, the grammatical expression oftense is mixed with the expression of mood and/or aspect (see Tense-aspect-mood).

In English, there are two verb forms which are commonly called "past tense", the so-called simple past, sometimes misleadingly called the preterite, which is a true tense, and the present perfect, which is generally considered an aspect rather than a tense.[1][2] These combine with other aspects including thecontinuous and progressive aspects to create several additional forms:

Simple past is formed for regular verbs by adding -d or – ed to the root of a word. Examples: He walked to the store, or They danced all night. A negation is produced by adding did not and the verb in its infinitive form. Example: He did not walk to the store. Question sentences are started with did as in Did he walk to the store?Simple past is used for describing acts that have already been concluded and whose exact time of occurrence is known. Furthermore, simple past is used for retelling successive events. That is why it is commonly used in storytelling.

Past progressive is formed by using the adequate form of to be and the verb’s present participle: He was going to church. By inserting not before the main verb anegation is achieved. Example: He was not going to church. A question is formed by prefixing the adequate form of to be as in Was he going?.

Past progressive is used for describing events that were in the process of occurring when a new event happened. The already occurring event is presented in past progressive, the new one in simple past. Example: We were sitting in the garden when thethunderstorm started. Use is similar to other languages' imperfect.

Present perfect is formed by combining have/has with the main verb’s past participle form: I have arrived. A negation is produced by inserting not after have/has: I have not arrived. Questions in present perfect are formulated by starting a sentence with have/has: Has she arrived?

Present perfect is used for describing a pastaction’s effect on the present: He has arrived. Now he is here. This holds true for events that have just been concluded as well as for events that have not yet occurred.

Present perfect progressive is formed by prefixing have/has before the grammatical participle been and the verb’s present participial form: We have been waiting. A negation is expressed by including not between have/has and been:They have not been eating. As with present perfect simple, for forming a question, have/has is put at the beginning of a sentence: Have they been eating?

Present perfect progressive is used for describing an event that has been going on until the present and may be continued in the future. It also puts emphasis on how an event has occurred. Very often since and for mark the use of presentperfect progressive: I have been waiting for five hours / I have been waiting since three o’clock.

Furthermore, there is another version of past tense possible: past perfect, similar to other languages' pluperfect.

Past perfect is formed by combining the simple past form of to have with the past participle form of the main verb: We had shouted. A negation is achieved by including not after had:You had not spoken. Questions in past perfect always start with had: Had he laughed?

Past perfect is used for describing secluded events that have occurred before something else followed. The event that is closer to the present is given in simple past tense: After we had visited our relatives in New York, we flew back to Toronto.

Past perfect progressive is formed by had, the grammatical...