first of all the eg you have given is slightly wrong.It should be wait kara hoga. and the answer of your question is that we use honge by respect and specially to elders. For eg ve log bus stop pe honge.And honga is not an hindi word. Hope you understand. :)

In many contexts they are exactly equivalent. However suitable has the meaning of simply being usable for a particular purpose, while appropriate has additional connotations of being non-offensive, of the proper register, etc.Something proper is correct or right. There's a proper fork to use for salad, and a proper way to dress for a wedding.