Which is correct grammar to say using correctly or using?

Both "using correctly" and "using" can be correct, depending on the context. Here's how to choose the right one:

"Using correctly" implies that you are emphasizing the correct way to use something.

* Example: "Are you sure you are using the equipment correctly?"

"Using" is more general and simply indicates that something is being used.

* Example: "I am using the new software."

In short, use "using correctly" when you want to emphasize the correct way to use something. Otherwise, use "using."