Relative clauses

[sky3120]

Hi, I learned and understood how to use relative clauses but what I want to know is that there is always a meaning difference between defining relative clause and non-defining relative clause?

I know that there is a meaning difference between two sisters who and two sisters, who...

However, sometimes I think it's not almost impossible to differentiate. For example,

The man who can speak English well , Jake is ....

The man, who can speak English well, Jake is...

In the end, in both sentences, we could know Jake can speak English well, so meaning is the same. Am I right? Or there is some meaing.difference or only one is acceptable?

This is a problem bothering me for a long time. Please help me get out it.

Thanks in advance.

[5jj]

You have complicated matters by adding 'Jake'; this appositional expression must itself be separated from the rest of the sentence by commas.

The man who can speak English well is called Jake.
Of those men we are considering, only one speaks English well. He is called Jake.
The man who can speak English well, Jake, works for my brother.
Of those men we are considering, only one speaks English well. That he is called Jake is given as additional information..
That man, who can speak English well, is called Jake.
'Man' is defined by 'that'. The non-defining relative clause simply gives us extra information about him.

[sky3120]

Thanks a lot. Then, I will make it simpler. There is always a meaning difference between defining relative clauses and non-defining clauses?

[5jj]

There is always a meaning difference between defining relative clauses and non-defining clauses?

Yes.