When to use the gerund form of a verb after "to"? [duplicate]

I would like to understand when to use the gerund form of a verb after "to." I had in my mind that every verb used after "to" was in its infinitive form, like for example:

1. It is hard to play the piano when your fingers are cold.
2. Call me if you decide to buy those pants.

However, I have come across sentences where this logic is not followed; for example:

1. I got used to reading in the bus.
2. He went back to studying mathematics.

This is getting me very confused, so I need some help with this.

Do you know the way to San Jose? Now there's a sentence which contains a to but no infinitive of a verb.

Your second group are a bit like that. The gerund is a noun (from a verb). So saying I got used to reading is grammatically no different to saying I got used to Michael.

Or He went back to studying just like He went back to Minneapolis.

But the infinitive is a different construction altogether, where the to precedes not a noun but a verb. In your first two examples one cannot substitute anything but a verb after the to.

There are certain expressions that take to + ing.

Here are some examples:

admit to: He admitted to stealing the money.

allude to: He alluded to being frightened.

amount to: Telling a half truth amounts to lying.

as an alternative to: As an alternative to driving, walking is recommended.

as a reaction to: He went into a rage as a reaction to being fired.

attach great importance to: Teachers attach great importance to writing tests.

attitude to: His attitude to eating is "eat to live, not live to eat".

attribute to: He attributed his success to making good investments.

accustom oneself to: be accustomed to: become/get accustomed to: He's accustomed to getting up early.

be agreeable to: He's agreeable to meeting on Friday.

be an obstacle to: Poverty is an obstacle to getting ahead in life.

(not) be averse to: He is not averse to telling lies to get what he wants.

be close to: The police are close to discovering who the thief is.

be committed to: He is committed to doing his best. commit oneself to:

be confined to: He confines himself to smoking one cigarette a day. confine oneself to:

(not) be conducive to: Noise is not conducive to studying.

be dedicated to: He is dedicated to helping the poor. dedicate oneself to:

be devoted to: He is devoted to helping the poor. devote oneself to: He devotes himself to helping the poor.
devote time to: He devotes time to helping the poor.

be given to: He is given to shouting when he is angry.

be limited to: limit oneself to: He limits himself to smoking one cigarette a day.

be looking forward to: He's looking forward to meeting you. look forward to:

be near to: The police are near to discovering who the thief is.

be opposed to: He is opposed to bringing back the death penalty.

be on one's way to: He's on his way to becoming a star.

be preferable to: Eating home cooked food is preferable to eating out.

be reconciled to: He's reconciled to living alone.

be resigned to: He's resigned to accepting his illness.

be the key to: Hard work is the key to succeeding in life.

be the secret to: Hard work is the secret to succeeding in life.

be/get/become used to: He's used to getting up early.

can't swear to: The witness couldn't swear to having seen the accused commit the crime.

come close/near to: He came close to being run over by a bus.

confess to: He confessed to committing the crime.

consent to: He consented to paying for the dinner.

contribute to: Loud music contributes to suffering loss of hearing.

due to: He got cancer due to smoking too much.

get round to: I must get round to answering those emails.

fall to: After being fired, he fell to wondering how he would survive.

feel up to: I don't feel up to walking there; let's take a taxi.

go back to When the baby was born, he went back to wetting his bed.

go a long way to; Love goes a long way to dealing with problems.

have a repugnance to: He has a repugnance to being touched.

in addition to: In addition to singing, he writes music.

lead to: His performance led to being nominated for best actor in a drama

move nearer to: Scientists are moving nearing to discovering a cure for AIDS.

object to: He objects to my smoking.

open the door to: Genetic research has opened the door to understanding hereditary diseases.

own up to: He will never own up to lying.

prefer (ing) to (ing): He prefers staying in to going out.

prior to: Lock the door prior to leaving.

refer to: As an example of domestic violence, she referred to his beating her up.

resort to: Being poor, he resorted to stealing to survive.

restrict oneself to: He restricts himself to smoking one cigarette a day.

revert to: When his baby sister was born, he reverted to wetting the bed.

see no alternative to: He could see no alternative to resigning.

share a commitment to: They share a commitment to helping the poor.

stick to: He should stick to acting; he doesn't have a good voice.

stoop to: He would never stoop to cheating at cards.

(not) take kindly to: He doesn't take kindly to being given advice.

take to: After being promoted, he took to ordering everyone around.

There are drawbacks to: There are drawbacks to living in the country.

There is more to: There is more to modelling than one would think.

There is not much to: There is not much to cooking, as long as you follow the basic recipe.

The trick to: The trick to succeeding in life is looking at the glass half full.

turn to: When he was nervous, he would turn to having a drink.

with a view to: He moved to the countryside with a view to living a healthier lifestyle.

with regard to: With regard to watching TV, I believe children should be allowed some freedom.

when it comes to: When it comes to showing affection, women are more demonstrative.

What do you say to: What do you say to going to the movies?