(continued from the previous post, which italki was rejecting because it was too long):
- To make things even more complicated, in English, infinitives *can* act as nouns (much like in Spanish), but not in every circumstance. It's less common than seeing the gerund, and so I wouldn't worry about it too much if you're just starting out with gerunds, but keep in mind that it can happen.
- The "present participle" is the "-ing" form of the verb that signifies a progressive verb. For instance, "He is sleeping" = "He sleeps (and continues to sleep)" - in Spanish, it's the equivalent of, "El esta dormiendo."
- Many people call the "present participle" in English the "gerund," to the point that they're sometimes considered interchangeable.
In terms of identifying these distinctions, I'd follow the following rules:
(1) If the word is a verb with "-ing" attached to it, it's either a gerund or a present participle.
(2) If the word is being used as a noun (for instance, if it's the first word in the sentence, it's a gerund. If it is being used to express a progressive verb or as an adjective, it's probably a gerund or present participle.