The Reference : if the word "Yet" it self is meaningless but if the word "Yet" is placed in negative sentence such changes the meaning of "tidak" tobe "belum" and if the word "yet" is placed ahead of subject to carry along meaning "namun or walaupun" such is called as conjunction but if the word "yet" is used in positive sentence to carry along meaning "masih". If the word "yet" is the meaning of "belum or masih" tobe used in BA as present perfect continuous tense, BAA as present continuous tense and AA as present tense such is showing the continuing deed.
Example
BA: Why have you not been being fluent to speak english?
BAA: Why are you not being fluent to speak english yet?
AA: Why are you not fluent to speak english yet?
Yet -subject (I,You,we,they,he,she,it)
conjunction - "Walaupun, Namun"
anyhow
although
eventhough
but
let
Example
BA. Let my the english conversation has been being still less but I have never been hopeless to practice english
BAA Let my the english conversation is being still less but i am never being hopeless to practice english
AA Let my the english conversation is still less but i am never hopeless to practice english