In your example 'to' is used as a preposition. 'To' often indicates a direction: Did you go to the doctor? Let's go to the cinema? Charlie is going to France next week. There are some common constructions 'verb + to' in English and it is best to learn them by heart: talk / speak to somebody listen to write (a letter) to apologise to somebody for explain something to somebody explain / describe to somebody what/how/why 'to' is not used with these verbs: phone / telephone / call somebody answer somebody/something ask somebody thank somebody for something 'to' is also used with the following verbs: happen to invite somebody to a party / a wedding prefer one thing/person to another Sources: English Grammar in Use by Raymond Murphy, Cambridge University Press and Grosses Handbuch Englisch Grammatik, Compact Verlag

We sometimes use one verb after another verb. Often the second verb is in the infinitive form, for example: * I want to eat. But sometimes the second verb must be in gerund form, for example: * I dislike eating. This depends on the first verb. Here is a list of verbs that are usually followed by a verb in gerund form: * admit, appreciate, avoid, carry on, consider, defer, delay, deny, detest, dislike, endure, enjoy, escape, excuse, face, feel like, finish, forgive, give up, can't help, imagine, involve, leave off, mention, mind, miss, postpone, practise, put off, report, resent, risk, can't stand, suggest, understand Look at these examples: * She is considering having a holiday. * Do you feel like going out? * I can't help falling in love with you. * I can't stand not seeing you.

There is no "why". Just accept it. You won't learn anything by busting your brains about it.

I think the main time we use "to" is when it is anytime you are using an infinitive. "To" is part of the verb in French. We say: I want to eat. French say: Je veux manger.