My question is specifically about adjectival present/past participles. I wonder whether all VERBS can be used to make adjectival present/ past participles. Say for examples...
1) A working man/ an eating dog/ a drinking cow/ a sitting cat/ a questioning student/ a scolding mum/ a playing kid/ a loading computer/ an operating machine/ a shouting man/ etc.
2) an upgraded computer/ an eaten cake/ blown hair/ a buried treasure/ a mocked person/ a teased friend/ a slapped woman/ etc.
I just want to do whether it is grammatical to "create" adjectival present/ past participles freely (as they come to our mind) to use in English.
then when can I know whether I can do that? Under what conditions, etc.?
There is, unfortunately, no simple formula to predict whether any given participle can serve as what Quirk et al. term 'central adjectives' (i.e. essentially, those that can be modified by 'very'), only vague tendencies dictated largely by convention, making this one of the most difficult areas of English grammar for the learner. Even the compendious CGEL has relatively little to say on the topic. Your best bet is to check each individual case with a native or good learner's dictionary.
So talking about the dictionary, the way that I can determine whether a verb+ing/ed can be an adjectival participle is SIMPLY to see whether the dictionary has marked the ing/ed form of a verb as an adjective right?
Just like: "frighten" is a verb, but the dictionary also introduces its brother "frightening" (the adjective) at the bottom. But you won't see "eating" as an adjective is introduced when you check the verb "eat" in a dictionary. So, does it mean that if I cannot find the ing/ed form of a verb introduced as an adjective in the dictionary, this "imagined" adjectival participle does not exist at all?
I suggest this:
(a) Go to Google.
(b) Type in the word that interests you.
(c) Click on the "books" section.
If that word is being used as an adjective, you will find it mentioned in the many books that
Google has digitized for our benefit. You will see that word used in a variety of sentences and in
all kinds of books (fiction, history, etc.)
But I want to be sure of 1 thing first: all available/usable adjectival participles, be they present or past, all appear in the common dictionary already?
You can never be sure of this. The way we use words changes all the time. "Helicopter" used to be a noun. Now you can say that supplies were helicoptered into the area that suffered and earthquake. Similarly, verbs that didn't used to work as adjectives may do so in the future, or a writer may use a word that way for a specific effect in a specific situation.
However, to take a conservative path, I think your idea makes sense. If you don't see it listed in the dictionary as an adjective, don't use it. Just don't be surprised if you see a native speaker using it in a way that you wouldn't have expected.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.