To has two different uses. It can be an infinitive marker. Examples are: to swim, to work, to break, to go etc.

• He likes to sing.
• She wants to go.
• You need to work.

To can also be a preposition. When to is a preposition, it can be followed by an –ing form, but not normally by an infinitive. This usually happens after expressions like look forward to, in addition to, object to, be used to and get round to.

In the following examples, the preposition to is followed by either a noun or an –ing form.

• I look forward to hearing from you. (NOT I look forward to hear from you.)
• We look forward to continuing our business relationship.
• I look forward to your next letter.
• I am used to her silly ways.
• I am used to working with all kinds of people.
• I object to Sunday work.
• I object to working on Sundays.

Exceptions

There are some exceptions to this rule. A few verbs that require to before nouns (e.g. agree, consent, entitled, inclined, prone ) are followed by infinitives, not –ing forms.

• I will agree to your suggestion if you lower the price.
• I will agree to do what you suggested. (NOT I will agree to doing what you suggested.)
• He is inclined to mischief.
• He is inclined to do mischievous things. (NOT He is inclined to doing mischievous things.)