Formal:
* Ek mis jou al. (This is the most literal translation, but it might feel a bit stiff)
* Ek verlang al na jou. (This translates to "I long for you already," and conveys a stronger sense of longing.)
Informal:
* Ek het jou al so baie gemis. (This means "I've already missed you so much.")
* Ek mis jou al baie. (This is a more casual way to say "I miss you already" and emphasizes the intensity of the feeling.)
Other options:
* My hart verlang al na jou. (This translates to "My heart already longs for you." This is a very romantic and expressive way to say "I miss you already.")
* Ek kan nie wag om jou weer te sien nie. (This translates to "I can't wait to see you again." While it doesn't directly say "I miss you," it implies it strongly.)
The best way to say it depends on the context and your relationship with the person you are talking to.