What is the ruling on saying: "Good morning," "Marhaba," and "Hi"?

Greetings like "Sabah al-khair" (Good morning) and "Marhaban" (Welcome) have been discussed previously. As for the word "Hi," it is a foreign term, and one should not communicate in languages other than Arabic unless there is a necessity. Furthermore, initiating a greeting other than "Salam" is not appropriate. A Muslim should be proud of his Arabic language and Islamic culture.