It’s quite common for kids at this age to leave off the ending and sometimes the beginning sounds of words, so you don’t need to worry about the way your son sounds at this point. For now, just model the correct way of saying the word and continue on. At this point, the main focus should be on helping him learn and use more words to express himself. Given that he does only say a few words, it never hurts to have him evaluated by a speech therapist. Feel free to “Ask Bundoo” if you want more specific advice privately!
Thanks, I will!