what are gerunds?
When a verb acts as a noun in a sentence, it becomes a gerund. It is always formed by adding '-ing' to the base form of the verb.
1. I amswimming.
2. I likeswimming.
In sentence 1 the word 'swimming' acts as a verb, however, in sentence 2, it acts as a noun. Thus 'swimming' is agerundin sentence 2.