Gerunds are verbs that end with -ing and act as nouns. For example, in the sentence “Reading is my favorite hobby”, reading is a gerund that is the subject of the sentence. Gerunds can also be objects of verbs or prepositions. For example, in the sentence “She enjoys swimming in the pool”, swimming is a gerund that is the object of the verb enjoys and the preposition in.
Some verbs are always followed by gerunds, such as enjoy, avoid, finish, mind, suggest, etc. For example, you can say “I avoid smoking” but not “I avoid to smoke”. Some verbs can be followed by either gerunds or infinitives without changing the meaning, such as like, love, hate, prefer, start, etc. For example, you can say “I like reading books” or “I like to read books” and they mean the same thing. However, some verbs can be followed by either gerunds or infinitives but with a change in meaning, such as remember, forget, stop, regret, try, etc. For example, if you say “I remembered to lock the door”, it means that you locked the door before leaving. But if you say “I remembered locking the door”, it means that you recalled the action of locking the door later.
Infinitives are verbs that are preceded by the word to and act as nouns, adjectives, or adverbs. For example, in the sentence “To travel is my dream”, to travel is an infinitive that is the subject of the sentence. Infinitives can also be objects of verbs or adjectives. For example, in the sentence “He decided to quit his job”, to quit is an infinitive that is the object of the verb decided. Infinitives can also be used to show the purpose or intention of an action. For example, in the sentence “She went to the library to study”, to study is an infinitive that shows the purpose of going to the library.
Some verbs are always followed by infinitives, such as decide, agree, hope, plan, promise, etc. For example, you can say “He agreed to help me” but not “He agreed helping me”. Some adjectives are also followed by infinitives, such as happy, sad, glad, ready, eager, etc. For example, you can say “She was happy to see him” but not “She was happy seeing him”. Infinitives can also be used after certain expressions, such as it’s time, it’s important, it’s necessary, etc. For example, you can say “It’s time to go home” but not “It’s time going home”.
There is also a form of infinitive without the word to, which is called the bare infinitive. The bare infinitive is used after modal verbs, such as can, could, may, might, will, would, etc. For example, you can say “She can speak three languages” but not “She can to speak three languages”. The bare infinitive is also used after some verbs of perception, such as see, hear, watch, feel, etc. For example, you can say “I saw him cross the street” but not “I saw him to cross the street”. The bare infinitive is also used after the verbs let, make, and help (optionally). For example, you can say “He let me borrow his car” or “He helped me (to) fix the computer”.
