Aspect is a construction in English grammar (not every language has aspect) that (1) relates to the passage of time and (2) identifies whether actions (occurrences, events, states of being, etc) that take place in time are completed or incomplete and continuing: If they are incomplete, they are said to be continuing. There are four aspects in English. The first is Indefinite Aspect, also called Zero or Simple Aspect. In Indefinite Aspect, the action of the verb has no relation to the passage of time; the verb is in its simple form (hence, Simple Aspect) and shows that an action, etc. did or did not happen: I ate. She walks. He will not come. They do not go.
The second aspect is Perfect Aspect. It is important to know how to form Perfect Aspect and what passage, or flow, of time this aspect indicates. First, it is formed with the auxiliary verb have (have, has, had) plus the -ed or -t past participle of an infinitive verb (regular or irregular, e.g., gone, arisen): e.g., climbed, combed, went, spent. It may indicate the flow of time as past (had climbed), present (have combed), or future (will have gone or will have spent).
Perfect Aspect indicates a passage or flow of time in which something occurred in the past and is completed, yet that past occurrence was before another point in time: I had combed the cat before the Cat Show last week. I have climbed Mt. Fuji before today. I will have spent more by next month than I spent last year. This indicates a past occurrence in reference to a fixed point in time: e.g., last week, today, last year.
The third aspect is Progressive Aspect. It is formed with the auxiliary verb be (be, is, was, am, are) plus the -ing present participle of an infinitive verb: e.g.; climbing, combing, going, spending. It too may indicate the flow of time as past (was climbing), present (am combing), or future (will be going).
Progressive Aspect indicates a passage or flow of time in which something is in the process of occurring, so the event, etc. is not completed. It indicates a condition of continuance: I was climbing the ladder when you phoned. I am combing the cat for the show this afternoon. I will be going to the cinema on Saturday.
The fourth aspect is Perfect Progressive and is a complicated one because it combines both Perfect Aspect and Progressive Aspect. It is formed by combining the auxiliary verbs have and be plus the -ing present participle of an infinitive verb. An example of Perfect Progressive associated with past tense is “had been climbing”; associated with present tense, “have been combing”; associated with future construction, “will have been going”.
Perfect Progressive indicates that a continuing occurrence progresses to a certain past, present, or future time. The action is incomplete and continuing until that certain time: I had been climbing all morning when the storm broke (past: continuing until the storm interrupted). I have been combing the wool all morning and still the basket seems full (present: continuing indefinitely). I will have been going to Arthur Murray dance classes ten years come May (future: continuing to a specified future date of completion, May in this case).
Tenses in English are named for their combination with aspects. Tenses locate events on a timeline from past to future, while aspect says whether the event is ongoing or finished and states the event’s relationship to other times and events in time: e.g., the cat show, the storm, the upcoming May, today, last week, etc.