In English, まだ
is regularly translated as ‘still’, or ‘not yet’, depending on if it is used in a positive non-past, or negative sentence. The reason that Japanese only requires one word for both of these nuances is due to まだ
literally meaning ‘something is unexpectedly still going’.
I am still running. (Although you probably didn’t expect it, I am still running)
My parents are still here, so I can't play games. (Although you probably didn’t expect it, my parents are still here)
I still have homework, so I can't hang out yet. (Although you probably didn’t expect it, I still have homework)
From these sentences, we can see that まだ
may be translated in each case as the following.
(Non-past) - Although (A) is expected to not be there/happening, it is. ‘Still’ in English.
(ている) - Although (A) is expected to not still be going, It is. ‘Not yet’ in English. The negative form of this will be discussed more in まだ～ていません
This is the opposite of もう
, which means ‘something is unexpectedly finished’.
may also be used to ask questions. This is when the speaker thinks that something ‘might’ be continuing, but wants or needs to confirm.
is often used simply as an expression indicating that something is ‘lacking’, or ‘not yet’ where it needs to be. In these cases まだ
is frequently repeated as まだまだ, for emphasis.