English verbs vary by type.
Some must take objects, some must not take objects, and some can either take them or not. As you may already know, some verbs are dynamic, but some are stative. Dynamic verbs show physical actions, but stative verbs are states or conditions.
Some verbs are modal verbs. That means they show possibility, ability, permission, likelihood, or obligation. Modal verbs behave differently from other verbs: they do not take an -s in the third person singular (he, she, it), they add the bare infinitive, they do not form participles, and they make questions by going before the subject of the sentence (inversion).
Some verbs are linking verbs. They link the subject to a noun, an adjective, a prepositional phrase, or a gerund phrase (see the index for a list of common linking verbs). Linking verbs show a condition or relation, not an action. To be, to seem and to become are always linking verbs.
Some verbs are one word (run, eat, go), but other verbs are phrases (wake up, take off).
Certain verbs such as beware are peculiar in that they do not take other forms. For example, there is no simple past of beware.
The clearest way to categorize verbs might be to say that there are only two classes of them: auxiliary verbs (have, do, will, is, are, am, was, were, be, being, been, has, had, do, does, did, need, to be able, shall, used, ought, dare, should, would, can, could, may, might, must) and all others (to eat, to drink, to follow, to learn, etc.).
All English verbs have these qualities:
Tense describes how grammar encodes the absolute location of an action in time. Strictly speaking, English only has two tenses: past and present. Inflecting a verb can show tense:
She plays the piano every day.
She played the piano last night.
To indicate the future we use a modal auxiliary (will) or a semi-auxiliary (be going to). But in modern English grammar we speak of English having twelve tenses. In this book we will learn all of them: the simple present, the simple past, the simple future, the present continuous, the past continuous, the present prefect, the present perfect continuous, the past perfect, the past perfect continuous, the future continuous, and future perfect, and the future perfect continuous.
Simple, continuous, and perfect are the three possible aspects an English verb. In linguistics generally, aspect shows how the action or state denoted by the verb relates to time—to the verb’s completion, continuity, bearing on the present, or repetition. Aspect tells us how the action is viewed with respect to time, but not the exact time of the action. In other words, aspect shows us how the action unfolds. In English, the simple aspect occurs in the simple past, simple present, and simple future tenses. The simple aspect does not use an auxiliary verb, except in the simple future. The simple aspect itself does not tell us if an action is complete or habitual. The continuous aspect uses to be + present participle. The perfect aspect is formed with has/have/had + past participle.
English has the imperative (demand, instruction, request, advice, command, entreaty), indicative (fact, denial, question), and subjunctive (contrary to fact, unreal, not fully real) moods. These tell the attitude of the speaker towards what they are talking about: are we speaking of facts, of something that is somehow unreal, or of something we wish to happen? In English, grammatical moods are expressed though sentence structure and changes in tense. The imperative mood, for example, is used for commands. Commands begin with a verb: Turn right!
Arisa eats an apple every day. (indicative-factual statement or question)
Arisa, eat the apple. (imperative-command
Let’s start. (imperative)
Don’t be late. (imperative with be)
Get your room cleaned up! (imperative with have/get)
I suggest she eat an apple. (subjunctive-not factual, not real, not yet real)
May he do well in all he attempts. (subjunctive-wish)
What time is it? (indicative-factual statement or question)
Come here! (imperative; the subject is an implied you)
I wish I spoke French. (subjunctive)
Voice shows the relationship of the subject to the action. The active voice shows the subject doing the action. The passive voice shows the subject receiving the action. In other words, the passive voice switches attention from the subject to the object.
Arisa is eating an apple. (Active)
An apple is being eaten by Arisa. (Passive)
My father wrote that book. (Active)
That book was written by my father. (Passive)