Verbal

I don’t know when and where to use verbal or verbal phrase:



The bird singing is a robin. Does it mean a bird is singing right now is a robin? ‘singing’ emphasizes the present continuous tense? Or it describes ‘the bird’, functions as an adjective? But I think there should be a Be-verb before ‘singing’ whatever if it represents the tense which is going on now or an adjective because in my concepts, ‘Be-verb’ + ‘present participle’ = present continuous tense. e.g. She IS PLAYING. Also, ‘Be-verb’ + ‘adjective’ e.g. I AM HAPPY.

There are more examples here which show you my point:

e.g. 1) Air pollution is a health problem affecting millions of Americans. Why there is the verbal ‘affecting’ here? Still no ‘be-verb’?

2) An uncertain future looming, immigrants face many obstables. Verbal ‘looming’? What’s it function? No ‘be-verb’? No any conjunctions connects the two parts?

3) For many immigrants learning English, the language introduces American culture. Verbal ‘learning’, What’s it use? No ‘be-verb’?

4) The immigrants having learned Englsh, their opportunities widen. What is the participle in the underlined part? I think ‘having’ and ‘learned’ are both participles. Still, the verbal ‘having learned’, what’s it function? Why not say: The immigrants have learned ...?

5) A question: We say: “Finally, making a conclusion” or “Finally, make a conclusion”?



Hope you can tell me the uses of the verbals in the sentences I gave above. Also, could you tell me when and where to use present participle ‘ing’ verbals ; and when and where to use past participle ‘ed’ verbals? Thanks so much!