TOEIC Grammar: Gerund or Infinitive? (-ing or to)

Some verbs take both forms. With begin, start, continue, prefer, like, love the meaning hardly changes. With remember, forget, stop, try the meaning changes:

• Please remember to lock the door. (a task still to do) / I remember locking the door. (a memory of a past action)
• He stopped to check his e-mail. (stopped in order to check) / He stopped checking his e-mail. (no longer checked)
• Try restarting the router. (as an experiment) / We tried to reach you. (made an effort)

Note allow / permit / recommend / advise: + object + to (allow staff to leave) or + -ing with no object (allow smoking only outside).

After prepositions: always -ing

Any preposition (in, on, at, for, of, about, by, without, before, after, instead of, despite) is followed by a noun or a gerund, never a base verb: Thank you for attending. She is responsible for training new staff. We cut costs by switching suppliers. Before leaving, turn off the lights.

To as a preposition

In some expressions to is a preposition, not part of an infinitive, so it is followed by -ing or a noun. The most tested ones are:

• look forward to, be committed to, be dedicated to, be devoted to
• be used to / get used to (= be accustomed to), be accustomed to
• object to, contribute to, in addition to, with a view to, when it comes to
• the key to, an alternative to, a solution to

We look forward to hearing from you. Pinewood Bank is committed to protecting your data. In addition to managing the budget, she supervises four staff members. Test: if you can put a noun after to (look forward to the meeting), to is a preposition, and the verb form is -ing.

Infinitives of purpose and after adjectives and nouns

The infinitive expresses purpose (We hired a consultant to improve our processes; also in order to), follows many adjectives (eager to, likely to, able to, pleased to, ready to, hesitant to) and follows nouns of plan and ability (a decision to, a plan to, the ability to, an opportunity to, an effort to, a chance to).

Quick check: (a) The firm has decided (opening / to open) a branch in Austin. (b) We are dedicated to (provide / providing) excellent service. (c) Please avoid (to park / parking) near the loading dock. — Answers: (a) to open, (b) providing, (c) parking.