Typically, when you have students who have no English language ability, you will be assisted by a native speaker with some English ability.
If an assistant is not available, you will have to use other means of communicating your ideas to the students using gestures, photographs, drawings, and pantomime.
A skilled ESL teacher may be able to utilize a more advanced student to communicate ideas in their native tongue which will instill confidence and a sense of responsibility in the assistant and create a more collaborative classroom.