When we use this symbol ( " ")?
Here is an example of it, but I cannot understand why the symbol is used.

Ex: On the other hand in the ("nonrelativistic ")case.....

Question

When we use this symbol ( "  ")?
Here is an example of it, but I cannot understand why the symbol is used.

Ex:  On the other hand in the ("nonrelativistic ")case.....

Answer

you can use () for more explanations or listing examples, whereas "" are used when you are quoting or directly copying someone else's words.

Answer

Thanks, Natalia

Answer

These are two symbols. () for words or phrases that explain something, but can be omitted and "" for quoting something or adding "so-called" meaning.