6/Sequence of tenses

If the tense of the predicate in the main clause is used in present or future tense, the tense form of the predicate in the subordinate clause doesn't change from the direct speech.

If the tense form of the predicate in the main clause is used in one of the past tenses then the tense of the predicative in the subordinate changes: present to the past, past to past perfect, and future to future in the past.

Sequence of tenses is typical of english verbs to show correlation of actions in a complex sentence. this correlation is evident in indirect speech when the predicate of the main sentence is used in the past tense. Then, the tense form of the predicate in the clause changes according to the following rules: present changes to the past, to past perfect and future to future in the past. there is a notion of historical present when present tense is used deliberately to make the narration more realistic and present is used instead of the past. in complex sentences, especially in fiction for emphatic purposes sequence of tenses may also be broken.The category of tense is interconnected with the more ancient category of aspect which is indicated in the name of the tense group like indifinite, continuous, perfect and perfect continuous. the category of tense in english is the most developed and complex grammatical category realized through the sixteen tense and aspect forms used with various frequency typical of different registers, for example, in spoken speech indefinite and continuous tenses dominate. for scientific and official styles indefinite and perfect tenses are characteristic. most complex perfect continuous tenses are not extensively used.

7 Tense and aspect categories.

In english there's a special word to describe grammatical realization of objective universal real time. in english there 16 tense and aspect forms to express 3 existing temporal relations, present, past and future. Apart from verbal expression of tense there are special temporal words, adverbs "now", "ago", nouns "today", "yesterday", phrases like "last year", "next months", etc., but the main part os speech to express temporal relations is a verb, so verbs locate an action in time. Verb simultaneously expresses another category of aspect which appeared earlier than tenseand is concerned with duration of action. All tense forms are concentrated near the moment of speech. it is a signal what tense should be used. Roughly speaking, in english there are only 2 tenses, past and present, because this opposition is formally expressed. There’s no ending to express future tense. to indicate the future tense we can use present tense or modal verbs shall and will. English has developed a special tense form called future in the past which is used in the sequence of tenses in reported speech. it is artificial creation. There’s also historic present in english when the present refers to past events to make past seem as it happens now. all present tense forms are considered the main in english because they include the moment of speech. all tense forms to the left of the moment of speech are called perfect and past perfect. all tense forms to the right of the moment of speech are future tense forms. Tense forms like perfect show that one action preceeds another. if the action occupies some segment on the tense axis and lasts for some period of time it will be continuous forms. Perfect continuous includes preceding and duration. Constant repetitive actions coinciding to the moment of speech are indefinite tense forms.

the usage of tense forms is regulated by language fashion in general tendencies of language developement. the most frequently used are indefinite simple tense forms continuous forms are more expressive than the otehrs, and there is a tendency to use statives.

More complex perfect continuous tense forms are rarely used at present.