Definition: The tense that expresses action in the past that has not been completed, that occurred habitually or frequently or that took place over an indefinite period of time. It is contrasted with the preterite tense, which expresses action that took place at a definite time or has been completed. English does not have an imperfect tense per se, although it has other ways of expressing the concept of the Spanish imperfect, as in the examples below.
Also Known As: Pretérito imperfecto in Spanish.
Examples:In Spanish: Él cantaba. Ella escribía la carta. Yo conocía a Eva. English equivalents: He used to sing. She was writing the letter. (Note that in the preceding two examples the reader can't tell out of context when or even whether the activity ceased.) I knew Eva. (Note that conocer, as in the Spanish example above, can mean "to know" or "to meet." The translation of "knew" is used because the use of the imperfect indicates an activity that didn't cease at a particular time.)