What are these ingforms of learning?

Question

1. He is learning English

2. I saw him learning English.

3. Learning is fun.

4. Learning English is fun

5. Learning a course in English is useful

In sentence 1, learning is the main verb. some call it present participle.

In sentence 2, learning is present participle.

In sentence 3, learning is a gerund .

In sentence 4, learning English is the subject and learning is modifying the noun English. So is learning an adjective here?

In sentence 5, “learning a course in English” is the subject.

What is learning here? Is it a gerund?.

Some linguists say it is better to call them ingforms to avoid the confusion.

I may sound naive but I hope I will get answers to my question.

Answer 1

I generally agree with Jeff Morrow's answer (though only some linguists treat a gerund as just a way of using a participle: many regard them as different forms which happen to have the same shape).

But I wanted to address your 4 and 5.

In 4, learning English is indeed the subject, but that does not mean that learning in any way modifies English: if it did, then the subject would be (some modified form of) English, but it isn't. The subject is the non-finite clause learning English, where English is the object of the gerund learning.

This points up the fact that, while gerunds in some ways behave like nouns, they are still verbs, and can take objects and adverbs like verbs. Your 5 gives a fuller example of this, where learning a course in English is again a non-finite clause acting as the subject.

Answer 2

In all these cases, "learning" is the present participle of learn.

A present participle can be used in conjunction with a form of the verb "be" to form a progressive tense of the verb with the root of the participle. I would say that the verb in

He is learning English

is neither "is" nor "learning" in isolation; instead, the verbal phrase "is learning" is the verb in the sentence.

A present participle can also be used as an adjective. For example, in the sentence

She was a very loving cat

the verb is "was" and "loving" is used as an adjective describing the noun "cat."

Finally, a present participle can be used as a noun representing the activity denoted by its root verb. It is then called a gerund.

Learning can be a joy.

So the word "participle" may refer to a form of a root verb, or it may refer to the syntactical use of that form. In the latter case, "gerund" just means a present participle acting as a noun.

I personally am not crazy about the ingform neologism because similar complexities arise with respect to perfect participles, which do not have an "ing" suffix.

Answer 3

[1] He is learning English.

[2] I saw him learning English.

[3] Learning is fun.

[4] Learning English is fun.

[5] Learning a course in English is useful.

In [1], [2], [4] and [5] "learning" is a gerund-participle verb. Note that in [2] "learning English" is a subordinate clause serving as complement of "saw". Note also that in [4] "English" is direct object of "learning"

In [3] "learning is fun" is strictly speaking ambiguous, but verb is the more salient interpretation ("To learn is fun"). Noun interpretation can be forced by adjectival premodification, as in "Occasional learning is fun".