some tips that might help:
- Don �t give very difficult tasks anyway. All your students are at a low level and it �s important for them to feel confident that they can do the tasks.
- When practicing grammar use only the simplest vocabulary in your sentences. When you teach for example the present progressive, focus on form only. If the grammar practice exercises contain difficult words they won �t understand anything.
- Include drill type exercises. The "older"students can revise acquired knowledge and the new ones can get familiar with the new forms.
- Subtly encourage the new students to answer the easier questions.
- Give supplementary material to the new students to study and learn at home during the weekend. A pictionary of basic verbs would be a good start I think.
- Generally try to use flashcards, pictionaries, matching etc for new vocabulary items.
- I think it generally helps weaker students to teach in topics, as Terri said.
Good luck with your new class!