Tense simplification: use would, could, might, should to express possibility, uncertainty, etc. in the present

Question

The book Practical English Usage by Michael Swan says: The tense in the subordinate clause tends to be simplified.

He gives some examples:

(a) If I (would have) had lots of money, I would give some to anybody who (would ask) asked for it.

(b) In a perfect world, you would be able to say exactly what you (would think) thought.

(c) I would always try to help anybody who was in trouble, whether I knew them or not.

And since Would has the meaning of will just with a softer tone, it got me thinking: What tense should I use when I use would to talk about the present and future, but with doubt, uncertainty, or possibility?

Examples I came up with:

(1) I would go to the park with her if she invites/invited me. =>I want to use "would" to express uncertainty in my willingness to go to the park.

(2) This thing is weird. I would think Tom is/was able to explain. =>I want to use "would" to express uncertainty in my thinking.

(3) I have this extra money on me. I would give it to friends who ask/asked for it. =>I want to use "would" to express uncertainty or possibility of giving money.

Do they have anything to do with tense simplification? If not, does it mean that I can use tenses depending on what I try to say?

By depending on what I try to say, I mean like:

I can use invites in (1) because it happens in the future.

I can use "Tom is able to explain" in (2) because it happens in the future.

And I can use either one of the phrases down below:

(4)use friends who asked for it to mean in the past, there were friends of mine that asked for money from me

(5)use friends who ask for it to mean the friends that might or will ask me for money in the future

Finally, how about could, might, should; I remember they can also be used to express uncertainty, doubt, etc. Do they follow the same rules?

Answer 1

I'll give a partial answer, in case it helps. It will take the form of the full expansions that I think your author is simplifying from. It is an interesting point; I rarely think about all the freedom we have to shorten these things.

But in general, I'll point out that all these words - should, would, will, can, might, may - give use quite a bit of freedom... a lot of experience listening and taking part in conversations will help build your confidence with what to do and when.

Here are my ideas on the full versions of these:

(a) If I had lots o f money, I would give some to anybody who asked for it.

Were I to have / If I were to have lots of money, I would give some to anybody who asked for it.

(b) In a perfect world, you would be able to say exactly what you thought.

Were we to live in a perfect world / If this were to be a perfect world, you would be able to say exactly what you thought.

(c) I would always try to help anybody who was in trouble, whether I knew them or no

I would always try to help anybody who was in trouble, whether it were true that I knew them or not

whether it were to be the case that I knew them or not

were I to know them or not (I guess the best, as it is shorter and I think gets it done)

Hopefully I am getting this right; as I say, it's been awhile since I noticed it.