[Xinfu]

Originally Posted by Rusty

"How's the Japanese going?" can be shortened to "How's the Japanese?" They both convey the same idea - the person is interested in hearing about the person's learning experience.
Some longer ways to say the same thing:
"How is the/your Japanese learning going/progressing?"
"How are your Japanese studies/classes going?"
"Are you doing well in your Japanese classes/studies?"

"How's your Japanese?" is asking about the level or skill one has in the language.
"How's your Japanese coming along?" is asking the same questions written above.

Thank you, Rusty~