Using YA and TODAVÍA, and deciding which one to use, is normally quite challenging for people learning Spanish as a foreign language. This is because most students search for a direct translation from English to Spanish, and this does not work at all.
Todavía no he comprado los regalos (I haven’t bought the books yet).
Todavía estoy pensando que regalos voy a comprar (I am still thinking what present I am going to buy).
In this extremely useful video, you are going to learn a new way to think about YA and TODAVÍA, that will allow you to quickly figure out which o these words you need to you ¡Vamos al vídeo!