Hello, Alex! Welcome to the forum.
I think your problem is distinguishing between the many uses of the
-ing suffix. It's especially these two comments that make me think so:
The boy is angry = This is an angry boy.
The girl is smiling(verb) = This is a smiling(participle) girl.
But why are these sentences in Present Continuous tense?
Why not:
The ball rolls or not The girl smiles?
If this sentence is in Present Continuous tense, then I understand. I can understand tenses.
But the whole sentence is written in the past tense:
The agents had tiny swords; the ghosts looked like little floating sheets.
The
-ing suffix is like a Swiss army knife of the English language; it can be used to do multiple things, and these things don't necessarily have anything to do with one another.
While the
-ing suffix can be used to form a sentence in the present continuous (or any other continuous tense), it doesn't mean that every time we see a word that ends in
-ing, it has something to do with the present continuous. The
-ing suffix can also be used to transform a verb into a
different part of speech, which may not have a tense at all. In your case, you're asking about
the present participle adjective. As an
adjective, it's no longer a verb, and it does
not have a tense.
What does it mean for a verb to be turned into an adjective? How does that feel? Why would we even do that?
Adjectives are arguably easier to use than verbs. Turning a bothersome verb that requires us to use tense and complex syntax into an adjective can make our sentence more compact, shorter, requiring fewer words to express the same idea, and perhaps even easier to understand for others. Instead of saying "I saw a girl who was smiling", and having to use a relative clause and the past continuous with its corresponding auxiliary verb in the correct form, I can save a few words by simply saying "I saw a smiling girl".
Here,
smiling functions as an adjective. We could say you saw a beautiful girl, or an ugly one. Just like
beautiful and
ugly,
smiling has no tense. It's an adjective.
But it's not just that it makes it easier for us. It also allows us to better express ourselves and make our sentences more elegant. We can change the focus of the sentence and rearrange the word order, add more information without making the sentence lengthy and unpleasant, and generally use the language more naturally. It's hard to imagine English without it, really.
What's the connection between a present participle adjective and the noun it describes? How does it relate to the verb it derives from?
The way I like to think about it is that a verb has its subject, and (not always) an object. If the circumstances are right, we can transform the verb into a participle. Depending on whether we want to describe the subject or the object of the verb, we need to use the present participle adjective or the past participle adjective respectively.
SUBJECT → VERB → OBJECT
This information → shocks → me
Astronomy → interests → me
This topic → confuses → me
I can transform these verbs into present participle adjectives to describe their subjects...
"This is shocking information."
"Astronomy is an interesting subject."
"This topic is confusing."
...or transform them into past participle adjectives to describe their objects...
"I'm shocked."
"I'm interested in astronomy."
"This topic makes me confused."
...and, technically speaking, the sentence below is grammatically correct...
"I'm shocked by this shocking information."
...though it's not a very natural sentence to say. We usually need either the present participle derived from the verb or the past participle, but not both. "This is shocking information" already implies that I'm shocked by it, so it's redundant to point it out twice.
I hope this helps.