There are some verbs in English that need different type of objects: either gerunds or infinitives. In order not to make a mistake students usually learn these verbs by heart. Besides, there are also such verbs that may be followed by both gerunds and infinitives, and the choice of the object type directly influences the meaning of a sentence.

Of course there are not so many verbs such as “forget” in English, but the reason for the choice of the infinitive or the gerund object each time will be different and will strongly influence the meaning of a sentence. And it’s a real challenge for advanced students.

Speaking about the challenge, did you forget... ehm... nervermind...