The infinitive – is a non-finiteform of the verb.There can be to-infinitive and bareinfinitive (the infinitive withoutparticle to)
Use the infinitive (+ to):1. After adjectives:My flat is easy to find.2. To express a reason or purpose:He is saving money to buy a new car.3. After the verbs: (can’t) afford, agree, appear, arrange, ask, be able to, beg, dare, decide, deserve, expect, fail, forget, happen, help, hope, intend, learn, manage, mean, need, offer, persuade, plan, prepare, pretend, promise, refuse, remember, seem, teach, tend, threaten, try, want, wish, would like, would prefer …:She will never learn to drive.They can’t afford to buy a computer.
Use the infinitive (without to):1. After most modal and auxiliary verbs: can, may, might, must, should, dare, had better, would ratherI can’t drive. We would rather stay in tonight.2. After make and let:My parents don’t let me go out much.My boss makes us work hard.
Use the gerund:1. After prepositions and phrasal verbs:I’m very good at remembering new names.She’s given up smoking.2. As the subject of a sentence:Eating out is quite cheap here.3. After the verbs: admit, advise, avoid, can’t bear, can’t help, carry on, consider, delay, dislike, deny, enjoy, envisage, fancy, feel like, finish, give up, have difficulty, hate, imagine, intend, involve, it’s no good, it’s (not) worth, justify, keep (on), like, love, mind, miss, postpone, propose, put off, recollect, recommend, risk, stop, spend time, stop, suggest…:I don’t mind getting up early.We couldn’t help laughing.
Remember!!! The gerund and infinitive build the negative forms with not: e.g. not to be, not being. Most verbs take the infinitive rather than the gerund. These common verbs can take either the gerund or the infinitive with no differences in meaning: begin, continue, intend, neglect, refuse, start.
Like, love, hate and prefer can also be used with either the gerund or the infinitive, but the gerund is more common when you are talking generally, and the infinitive when you talk about a specific occasion:I like skiing (in general).I like to go skiing in February or March (specific). The verbs see, hear, watch and feel can be followed by an object + a base form to talk about a completed action, or an object + an -ing form to talk about an action in progress:I saw John drop his wallet in the street, then pick it up.I saw Amily playing football in the park.
These verbs can take the gerund or the infinitive but the meaning is different:1. Remember to lock the door. (you remember first, then you do something) I remember going to Venice as a child. (you do something, then you remember it)2. Sorry, I have forgotten to do it. (you didn’t remember to do something) I’ll never forget seeing London. (you did something and you won’t forget it)
3. I tried to open the window. (make an effort to do something) Try calling Miriam on her mobile. (an experiment to see if something works)4. You need to clean the car. The car needs cleaning. (passive construction: the car needs to be cleaned)