What's the difference between a participle and a gerund?

The difference between a participle and a gerund is the difference of part-of-speech usage, the difference of being a predicative after a verb and the difference of being an attribute to modify a noun.

Part-of-speech usage difference: the so-called gerund is a noun, but on the one hand, it retains some characteristics of verbs and adds some variants of verbs to express more complicated ideas that nouns cannot express. On the other hand, gerunds are similar to nouns in sentences in usage and function, and can be used as subject, object, predicative and attributive in sentences. It can also be modified by adverbs or used to dominate objects.

The present participle is equivalent to an adjective and is used as an attribute or adverbial in a sentence, so when v-ing is used as a subject, object and appositive in a sentence, it is definitely a gerund, and when v-ing is used as an adverbial in a sentence, it is definitely a present participle.

The difference between predicate and copula: the gerund and subject as predicate refer to the same thing. At this time, the copula is equivalent to "yes", and the positions of subject and predicate are usually interchangeable. The present participle as predicative is mainly used to explain the nature of the subject and cannot be interchanged with the subject.

The difference between modifying nouns as attributes: gerund mainly indicates the purpose of nouns when modifying nouns. Nature, state, behavior, etc. When the present participle modifies a noun.

Sleeping child: a sleeping child. The present participle sleeping indicates the state of the modified noun child. Sleeping car: a car used for sleeping, and the gerund sleeping indicates the purpose of the car.