I think it’s great that you’re starting to teach your mother and a teacher English. It will be good for them and when you teach them, you will revise a lot of language yourself.
The basics of English language teaching are grammar, vocabulary and functions. Functions are set phrases used in different situations – e.g. the language of ordering food in a restaurant, the language of introducing oneself to strangers… Apart from grammar, vocab and functions, it is important that students acquire 4 skills: speaking, listening, reading and writing. Pronunciation is also important; some people consider it to be an extra aspect and others include it in speaking.
The first thing to do is to work out what level your mother and the teacher are at: are they complete beginners, pre-intermediate, etc? Then look at which of the four skills are most important to them: e.g. will they mostly be using oral English? If this is the case, you will need to focus on speaking, listening and pronunciation. Also think about how they will use English: e.g. what is your mother’s job? Then choose vocabulary that will be relevant to her at work. How will they use English? E.g. does your mother use English on the phone or write letters? If so, teach her functions and set phrases to use on the phone or in letters.
When you have the answers to these questions, you should choose a textbook. Bear in mind their level and how they will use English. You will also need to choose between a general English course book and a business English one. Textbooks are structured and work on gradual progress which will make it easier for you to plan lessons.
When you are teaching, try to keep a balance between grammar, vocab, functions and the skills. If you spend an hour working only on grammar exercises it won’t be very interesting and your students might get demotivated. Also give them some work to do between classes; this can be exercises that revise what you have studied or prepare them for what will be covered in the next class.
I hope you will enjoy this experience. Please write in again if you have any other questions. You can also look at my answer to Carol on 4 April 2004.