[shí zai]

The work is well-done.
工作做得很實在。

[shí zài]

real ability
實在的本事

solid learning
實在的學問

He is honest in business.
他做生意很實在。

very good indeed
實在太好了

He pretends to understand, but as a matter of fact he doesn't.
他裝懂，實在并沒懂。