This is the 353rd most frequent Turkish word.
size
The Turkish word "size" means "to you" or "for you" (formal or plural).
In this sentence, 'size' is used as the dative form of 'siz' (you - plural or formal singular), indicating the recipient of the action.
Size bir hediye aldım.
I bought you a gift.
Here, 'size' indicates for whom the advice is considered beneficial, serving as the dative form of 'you'.
Bu tavsiye size çok yardımcı olabilir.
This advice could be very helpful to you.
In this context, 'size' identifies the recipient of the speaker's wish or message, utilizing the dative case.