Tense and Aspect
Tense is the grammatical expression of the location of events in time. Tense in verbs express the time that an action occurs in the moment of speaking. There are three types of tense in english grammar. These are present, past and future tenses. One important structure that functions together with tense is aspect. Aspect is a grammatical category that indicates temporal features such as duration, frequency, and completion. Aspect expresses how the speaker views of the verb. Aspect is indicated by complex tenses that are composed of an auxiliary verb + a main verb. There are two different aspects in English: the progressive and the perfect. We use the label progressive because the verb phrase describes the ongoing nature of an event or action. A progressive verb phrase consists of the auxiliary be in either present or past tense + the present participle of the main verb.
Progressive Aspect subject auxiliary be present participle (verb+ -ing) time reference John is walking. present John was walking. Past
When have combines with a main verb, the verb phrase shows the perfect aspect. The perfect aspect describes the relationship between an earlier event or action with a later event or action. A perfect verb phrases consists of the auxiliary have in either present or past tense + the past participle of the main verb. Perfect Aspect subject auxiliary have past participle (verb + -ed) time reference
John has walked. present
John had walked. past
John had