"See you when I see you" is an informal and casual way of saying goodbye. This phrase can be replaced with various synonyms depending on the situation and the level of formality. One could say "until next time" to signify a definite plan to meet again. "Take care" is a kinder way to say goodbye, expressing concerns for the person's well-being. "Farewell" has a more formal connotation and is commonly used in more professional settings. Other synonyms include "catch you later," "see you soon," and "goodbye for now." In every case, the goal is to express a final farewell while leaving the door open for future meetings.