“it doesn't matter ~” vs “no matter ~”

Question

I think if I can use "it doesn't matter ~", then I can also use "no matter ~". So to understand it more deeply and make sure of it, I've made two sentences and I'd like to know if these two sentences are the same meaning.

1. Whether it's in the library or in a coffee shop, it doesn't matter where you study. What's more important is if you have an willingness to study hard.

2. No matter where you study, whether it's in the library or at a coffee shop, what's more important is if you have an willingness to study hard.

Answer 1

In your example the meanings are the same, but you have to be careful about overapplying the similarity. They are not always interchangeable in all contexts. For example:

Q: Do you want me to order a pepperoni pizza, or a mushroom pizza?
A1: It doesn't matter; they both sound good to me.
A2: No matter; they both sound good to me.

If I am asked to choose between two options, and I don't have a preference, I prefer to use it doesn't matter, rather than no matter. So, in the dialog above, I'd probably answer with A1 and not A2.

I'm more likely to use the phrase no matter when I'm trying to reassure someone about something negative that has happened.

Ted: Sorry I spilled your beer.
Ned: No matter – there are plenty more in the fridge.

The two have a lot of overlap in meaning, but there are times I'd be more inclined to use one rather than the other.

Answer 2

In both sentences, "have an willingness" should be "have a willingness". An even more natural option is "are willing".

There is another slight problem with the second sentence. If you use "no matter", the clause becomes an adverbial clause modifying the main clause. This means that willingness to study doesn't have anything to be compared to anymore; "where you study" now modifies "is" in "what's more important".