While many languages convey this through distinct verb forms, English often does not. Native English speakers need to add these concepts to their vocabulary if they want to understand and discuss complex grammatical points.
Person: Who or What is the Subject of the Verb?
Person refers to the relationship between the subject of the verb and whomever is speaking. There are three types of grammatical person:
- First Person: The person(s) who is the subject of the verb is the same one who is speaking ("I know," "We understand").
- Second Person: The person speaking is referring to another person(s), assumed to be present, who is the subject of the verb ("You are right," "Thou art a fool").
- Third Person: The subject of the verb is not directly related to the speaker; the subject is not assumed to be present as "part of the conversation" ("He says," "She feels," "It goes," "They run").
Number: How Many Persons are the Subject?
Grammatical number refers to how many persons are the subject of a verb. In English, this is represented by either singular ("He sees") or plural ("They see") verb forms.
Tense: When is the Verb's Action Occurring?
Tense is the time in which a verb takes place. Languages distinguish between past, present, and future, but subdivide these three major categories in different ways.
Tense can also be used to subordinate actions in a sentence. For instance, the pluperfect tense is used for actions completed before a primary verb when the primary verb is itself a completed past (or perfect) tense: "After I had gone (pluperfect) to the store, I went (perfect) home."
While such constructions are more precise, it has become common in English not to subordinate: "After I went (perfect) to the store, I went (perfect) home."
Aspect: Is the Verbal Action Complete or Ongoing?
Aspect refers to the duration of a verb's action. It is usually simple (a completed action) or progressive (continuing action).
Aspect is related to tense, and many languages distinguish tenses by their aspect. For instance, the perfect tense is a simple past tense (I went), whereas the imperfect is a progressive past tense (I was going). As with tense, English tolerates less precision regarding aspect than other languages.
Mood: What is the Verb's Expression of Fact?
Grammatical mood refers to the type of expression a verb is making. It comes in three main categories in English, though others exist (especially in other languages).
- Indicative: verbs in the indicative mood express matters of fact ("You are going away now," "I was well"). This is the most common grammatical mood.
- Subjunctive: this mood can express an indirect command, wish, or contrary-to-fact situation ("You may go away now," "If I were well ..."). English has many ways of expressing the subjunctive, although it is often done imprecisely. Auxiliary verbs such as may, might, should, could, and ought are often part of subjunctive verb forms.
- Imperative: this mood expresses a direct command ("Go away now, you!" "Be well!"). It is by definition addressed to a second person.
Voice: Is the Subject Performing the Verbal Action?
Voice describes the relationship between the action or state described by a verb and the verb's subject. When the action is being performed by the subject, the verb is in the active voice. When something else is performing the action upon the subject of the verb, it is in the passive voice.
For instance, in the sentence "I drive the car," the verb to drive is in the active voice. In the sentence "The car is driven by me," the verb to drive is in the passive voice.
Like most languages, English has an active and a passive voice. Some other languages, such as Ancient Greek and Old Icelandic, also have a middle voice, in which the subject both performs the action, and has the action performed upon it. An echo of this occurs in Latin, which has deponent verbs that are passive in form but active in meaning.
Without an understanding of verbal forms that indicate person, number, tense, aspect, mood, and voice, it is very difficult to explain how verbs work or to discuss grammatical problems.
Such an understanding is important for native speakers of English, since it expresses verbal forms through context more often than through morphology or the use of auxiliary verbs.