You may recall that a verb is a word that expresses an action or occurrence. There are a few different types of verb forms that you'll want to be able to identify and use correctly in sentences. One type of verb form is the infinitive, which consists of the word 'to' plus the base form of a verb. You can think of an infinitive as kind of the raw form of a verb that hasn't been conjugated, paired up with a subject or assigned a verb tense.
Examples of infinitives include:
- to run
- to go
- to worry
- to be
- to drive
An infinitive phrase consists of an infinitive plus any additional words that describe the action expressed by the infinitive. For example, the phrase 'to get up early tomorrow' is an infinitive phrase. Another example is 'to get a new job.'
One important thing to remember about infinitives is that you can't have an infinitive phrase hanging out by itself, as it would be a sentence fragment, or incomplete sentence. That makes sense because if you were to announce, 'To get a new job!' or 'To get up early tomorrow!' and then run off, you'd leave people confused by your incomplete idea.
Because an infinitive is a sort of raw form of a verb, that means that we would have to do something to an infinitive for it to function as the main verb in a sentence, or that we would have to use the infinitive in some other way - not as the main verb.
Take the infinitive 'to conquer,' for example. As I mentioned, it wouldn't work to use this raw form as a main verb in a sentence. I wouldn't say, 'Jane finally to conquer her fear of kittens.' I could, however, use the past tense form of the verb and say, 'Jane finally conquered her fear of kittens.'
I could also say, 'Joe conquers cockroaches for a living,' or 'Sandy will conquer her math test on Friday.' In these sentences, I haven't used the infinitive raw form 'to conquer.' Instead, I've used forms of it as main verbs, and I've made sure that my subjects agree with my verbs and that I've used the right verb tense each time.
Keep in mind that you can use infinitives in sentences. You just can't use them as main verbs. For example, I could use an infinitive as the subject of a sentence: 'To study grammar is the best possible thing one can do.' In this sentence, the complete subject is the infinitive phrase 'to study grammar,' and the verb is 'is.'
Another type of verb form that has a few special rules for usage in sentences is the participle. There are two types of participles. A present participle is a verb form that ends with -ing. Present participles are often used as adjectives. You may recall that an adjective is a word that describes a noun or pronoun.
An example of a present participle is the word 'sleeping.' Here's how it would be used as an adjective in a sentence: 'The sleeping dog twitched its tail.' Here, the present participle 'sleeping' describes the noun 'dog.'
Present participles can be used as verbs, but they aren't complete verbs when used by themselves. Just as with infinitives, you can't use a present participle as the main verb by itself in a sentence. You'd need to add something to it. For example, you wouldn't say, 'Jamal studying for his test.' This is technically an incomplete sentence, or sentence fragment.
You'd need to add something to the present participle 'studying.' In this case, you would add a helping verb - a form of the verb 'to be.' A corrected version of this sentence would be 'Jamal is studying for his test.'
There's a second type of participle, and the rules are somewhat similar. A past participle is a verb form that usually ends with -ed or -d. Some verbs, called irregular verbs, don't follow the typical patterns that most verbs do. Irregular verbs have past participles with a variety of endings that don't necessarily follow a set pattern. That's because irregular verbs are - you guessed it - irregular. Many past participles end with -t, -en, -n or -ne, though that's not a complete list.
Some examples of irregular verbs are: