What is the difference between a gerund and present participle? When should we use a gerund and when should we use a present participle ?
The distinction between a participle and a gerund is troublesome. It looks as if the difference is to do with parts of speech or something similar. In fact, the real distinction has to do with the grammatical relations (syntactic functions).
In traditional grammar, a gerund is an -ing form of a verb that heads a phrase functioning as a:
- Subject of a clause
- Object of a verb
- Complement of a preposition
In all other situations, an -ing form of the verb is considered a participle. Phrases headed by participles are often modifiers in clause or phrase structure.
Some modern grammars such as the Cambridge Grammar of the English Language (2002) regard the distinction between gerunds and participles as unhelpful, because it blurs the line between what type of word the -ing form is and what job it is doing in the sentence. They use the term gerund-participle to refer to the type of word regardless of what job the phrase is doing in the larger sentence.
There is no difference. English only has -ing words. These are a completely regular inflectional form of the verb. And there is just one of these, not two.
"Gerunds" and "present participles" are meaninglesss relics from Latin grammar that do not apply to English.
No morphological distinction exists, and therefore they are the same word. It is not possible to use one instead of the other, nor vice versa, because these are not two different forms.
Therefore the answer to your question is that it does not matter. You cannot go wrong.