You can read about what verbs are, and their most straightforward and commonly used forms and tenses on the page about verbs in English grammar. This page describes the more complex use of verbs.
Verbs in the perfect tense
In addition to the three main tenses (past, present and future), there are three more complex forms, known as the perfect tenses, also with past, present and future forms. They are characterised by the auxiliary words have, has, had, shall have, or will have, combined with the past tense of the verb. The meaning is subtly different from the basic form of the tenses, in implying something which is completed.
For instance, ‘I have walked a long way today’ is the present perfect tense of ‘walk’. ‘I will have walked ten miles by tomorrow’ is an example of the future perfect tense. ‘Before I broke my leg, I had walked everywhere’ is an example of the past perfect tense.
Verbs in different persons
Verbs also change their form slightly, depending on who or what is being described in relation to the verb. Unlike some other languages, most verbs do not vary much in this respect. Already shown above, we say ‘I run‘ but ‘John runs‘. The only difference is the extra ‘s’ on the end when talking about another person.
Grammarians recognise three different ‘persons‘ in verb forms. If I am doing something, I’m writing in the ‘first person‘. If I am describing what you are doing, it’s the ‘second person‘. If I’m writing about someone else (male or female), it’s ‘third person. All these are ‘singular’ since they’re just one single person at a time. If I want to describe what several of us (‘we‘) are doing, that’s the ‘first person plural‘. If I’m talking about you and some of your friends, that’s ‘second person plural’. And if I’m talking about two or three other people (‘they‘), it’s ‘third person plural‘.
All that sounds very complicated, whereas the verb forms are in fact quite simple in English. We say: I walk, you walk, he/she walks, we walk, you walk, they walk. The only change is that for the first person singular, we add an ‘s’. This is true for the vast majority of verbs, regular or irregular, with the only slight variation being the ones that end in a consonant followed by ‘y’, where we remove the y and add ‘ies’. So: I cry, he cries; I reply, he replies; I fly, he flies.
For the past tense, all forms are identical, and the future form of the verb also stays the same for each person, with the auxiliary word ‘will’ or ‘shall’ immediately in front (eg I will run, you will run, he will run).
The verb ‘to be’
There is one verb which breaks almost all the rules – oddly enough, it seems to do so in many languages. That is the verb we call ‘to be’ – used mostly as an auxiliary word, but it’s a verb in its own right too, expressing a state of being. The first person form of this verb is ‘I am‘, but we then say ‘you are‘ and ‘he/she is‘. The plural form is simpler, the same as the second person singular: we are, you are, they are.
The past tense of ‘to be’ is different again, though slightly simpler: I was, you were, he was; we were, you were, they were. The present participle is ‘being‘, and the past participle is ‘been‘. And although the word ‘be’ is not used in any of the present forms, it is actually the present form of the verb which is used in the future tense: I will be, you will be, etc.
Progressive forms of verbs
The above constitutes the main verb forms, but from a grammatical perspective there are still more. One of the more commonly used is the progressive form, which consists of the relevant form of ‘to be’ as an auxiliary word, and then the present participle. There are six forms of this, reflecting the three basic tenses and the three perfect tenses. So:
Present progressive: I am running, you are running, she is running (etc)
Past progressive: I was running, you were running
Future progressive: I will be running, you will be running
Present perfect progressive: I have been running, you have been running
Past perfect progressive: I had been running, you had been running
Future perfect progressive: I will have been running, you will have been running
Transitive and intransitive verbs
So far most of the verbs can be used (with or without auxiliary verbs) with just one noun: John is climbing, Mary will be running, the cat purred. These verbs are all intransitive. Some verbs, however, make no sense when used in this way. We cannot, for instance, say as a sentence ‘I became’ or ‘you took’ or ‘he said’. The verbs ‘become’, ‘say’, and ‘take’ are transitive – they need something else after them. We can say ‘I became sick’ or ‘I became a mother’; we can say ‘you took a long time’, or ‘you took my scissors’. The word after the verb does not necessarily have to be a noun, but there has to be something afterwards when using a transitive verb.
Active and passive voice
Transitive verbs can have what is known as ‘voice‘ – a distinction that tells us whether the subject of the verb (the person or thing to which the verb refers) is doing something, or having something done to them. If the subject of the verb is doing the action, the verb form is active. For instance: The dog took the bone. The dog is the subject of the sentence, the bone is the object. (For more about nouns as subject and object, see the page on nouns).
However, if we want to think more about the bone than the dog – for instance, if we’re writing about making some soup out of lamb bones – we might say, ‘The bone was taken by the dog‘. The bone is then the subject of the sentence, but the bone doesn’t do any action – it is in the passive voice.
Most of the time, we talk and write using the active voice, but sometimes people write formal documents in the passive voice. To express that concept in the passive voice, I would say: ‘some documents are written in the passive voice‘. It’s a useful form to be able to use in formal writing, if you want to make a point succinctly, but should rarely be used in everyday speech.
For more examples, here are a couple of sites that may help:
Wikipedia on verb tenses – some historical and linguistic background,detailed description of how verb tenses work, and even more complexity.
Verb tense tutorial – lots of exercises to fill in gaps interactively, if you’d like to learn more about verbs and ensure you understand the different tense forms.
For further information on English grammar, see:
Basic English grammar – why it’s worth studying, an overview of the different parts of speech
Nouns – different uses of nouns, with plenty of examples
Pronouns – how to use pronouns, and their different uses in sentences
Adjectives – what adjectives are, how to use them, comparative and superlative forms
Adverbs – what adverbs are, when and how to use them