I would like to put some explanations about this, I am not sure if I am allowed to do so or not, since teachers are the ones who are allowed to answer the question and i am not a teacher, any way I will put what I have here and you can reject it if i am not allowed.
Originally Posted by jiang
First of all (according to the Grammar book I have), there are some verbs come in the form (verb + verb + ing) and you can't use the form (verb + to + verb) with these verbs and vice versa. These verbs you have to memorize them well. The following are some of these verbs:
(verb + verb + ing): stop, delay, facny, consider, admit, miss, involve, finish, postpone, imagine, avoid, aeny, risk, practice
(verb + to + verb): offer, decide, hope, deserve, attempt, promise, agree, plan, aim, afford, manage, threaten, refuse, arrange, learn, forget, fail
Some times when you don't use them often, you may face difficulty in remembering them, and you may ask yourself "what should I use?, should I put 'ing' or 'to...'?". Then, let me give the following rule:
(verb + verb + ing): usually '-ing' is used for an action that happens before the 1st verb or at the same time.
(verb + to + verb): usually 'to..' is used for an action that follows the 1st verb.I hope this would make it clear to you.