A typical context in which rules of sequence of tenses apply is that of indirect speech.
In English, an attracted sequence of tenses (backshifting) is often used in indirect speech and similar contexts.
For example: However it is also possible to use the natural sequence even if the main verb is past or conditional: This option is more likely to be used when the circumstance being expressed remains equally true now as it did when the speech act took place, and especially if the person reporting the words agrees that they are true or valid.
[2] Use of the attracted sequence sometimes leads to additional problems when the grammatical construction of indirect speech includes an incorporated quotation – that is, when an attempt is made (though using indirect rather than direct speech) to report the words actually spoken.
Indirect speech in Russian and other Slavic languages generally uses the natural sequence of tenses (there is no backshifting).
For example, when the subordinate verb refers to a time contemporaneous or later than the time of the main verb, the present or imperfect subjunctive is used: When the subordinate verb refers to a time earlier than that of the main verb, the perfect or pluperfect subjunctive is used: If the main verb is a historic present (i.e. a present tense with a past meaning), either primary or historic sequence may be used, or in a long sentence even a mixture of the two: If the main verb is a perfect tense, it is usually followed by the historic sequence, but if the meaning is equivalent to an English present perfect (i.e. "have done"), it may be followed by primary sequence: There are frequent exceptions to the sequence of tenses rule (see Latin tenses#Sequence of tenses rule).
The present infinitive is used for a situation contemporaneous with the main verb:[5] The perfect infinitive is used for an event or situation earlier than the time of the main verb: However, subordinate clauses in an indirect statement use the subjunctive mood, which is subject to the sequence of tenses rule: In Classical Greek, the tenses in subordinate clauses must correspond to those in the superordinate clauses governing them.
Such a historic tense is followed by:[7] The set of rules comprising the sequence of tenses (and modes of the main and subordinate clauses) in the Italian language corresponds in general to the "consecutio temporum" of the Latin grammar.