English Problems

I teach English once a week. So it's many problems. My students in prathom 1-3 can't write a-z. It's terribly. I don't know how to teach them write. But I tell them they have to work with my homework. I meet one of the class once a week. So they lost how to greeting me when I come in to their class. They can't remember "Good moring" that is use in the morning. They greet me "Good afternoon" in my morning class. And the captain can remember how to tell the classmates stand up.