Think of it this way Barb: Noone taught you first, second and third person singular or plural when you learned English. Correct grammar is "intuitive" for most native speakers. And, unless one has a particular interest in grammar points and form, most people are satisfied to only speak or write the language correctly without needing to understand the reason for this or that being stated in one particular way over the other.

This is the same tact you need to take when teaching beginning ESS/EFL students. If you are trying to "explain" the language to them, well, that's your first mistake. Simply model the language. Stay with subject pronouns and be verbs as long as necessary. "I am a teacher." "You are a student." "She is a student." "He is a student." "They are students." "Is he a student?" "Is she a teacher." "Are you students?" It shouldn't be long before you can move on to this, these and those. "This is a book." "Is this a book."

Well, you get the point. There is a structural sequence to teaching ESL/EFL that should be followed closely. Don't worry about being to creative in the beginning stages, but try to make it interesting. Personalize as much as possible. Use pictures and/or graphics as much as possible. Set the stage for internalization of the language as quickly as as you can and avoid being a lecturer. Think of yourself as a guide - not a teacher. When in doubt, think about how you learned your first language. Were you "taught" the language?

Good luck!