The use of "could", "may" and "might" in my sentence

[Rachel Adams]

When talking about the weather either "could", "may" or "might" is used. "Сould" means it's not impossible, it's not a prediction, "may" is used for permission not prediction, "might" is used and it is stronger than "could". This is what I have learnt from the forum discussions when using modals to talk about the weather. But do the same explanations apply to their use in other situations? For example to the second example?

1. "Take a coat. It may/might/could rain later."

2. "She could/may/might be Dave's sister. She looks like him."

The examples are from "English Grammar in Context" by Michael Vince.

 

[5jj]

Re: The use of "could", "may" and "might" in my sentence

When talking about the weather either "could", "may" or "might" is used. "Сould" means it's not impossible, it's not a prediction, "may" is used for permission not prediction, "might" is used and it is stronger than "could". This is what I have learnt from the forum discussions when using modals to talk about the weather.

Then you have picked up the wrong message.

It could rain this afternoon.
It might rain this afternoon. I don't see how that is 'stronger' than 'could'.
It may rain this afternoon. That has nothing at all to do with permission.

All of those are possible.

I am sure you have been told that different people understand may and might in different ways.

 

[Rachel Adams]

Re: The use of "could", "may" and "might" in my sentence

Then you have picked up the wrong message.

I am sure you have been told that different people understand may and might in different ways.

It was written by one of the native speakers that "might" indicates a stronger possiblity." Yes, I know you have different opinions about them. I know that one of the sentences has nothing to do with permission. I have also been told that native speakers don't use "may" for predictions. But my question is how does their meaning change in a situation when we are not making predictions?
2. "She could/may/might be Dave's sister. She looks like him."

If when talking about the weather "could" isn't the best choice but it's "might", "may" is used to talk about permissions so some native speakers wouldn't use it in the first sentence does the same use apply to the second sentence when we are talking about possibility and is each commonly used?

 

[emsr2d2]

Re: The use of "could", "may" and "might" in my sentence

In my opinion, we don't have specific words for degrees of possibility.

 

[Rachel Adams]

Re: The use of "could", "may" and "might" in my sentence

In my opinion, we don't have specific words for degrees of possibility.

So the meaning of these modals in such sentences is the same, isn't it? 2. "She could/may/might be Dave's sister. She looks like him."

 

[Tdol]

Re: The use of "could", "may" and "might" in my sentence

Not much, though for some people may is more likely.

 

[Rachel Adams]

Re: The use of "could", "may" and "might" in my sentence

Not much, though for some people may is more likely.

But what is the difference between them in such context if it's not the same?

 

[emsr2d2]

Re: The use of "could", "may" and "might" in my sentence

The fact that some people might choose one over the others doesn't mean that the meaning is any different.

"I have a pet feline" and "I have a pet cat" mean the same thing. Almost everyone would choose "cat" but that doesn't mean that "feline" means something different.