What do you mean "who doesn't do english", is he/she an international student who has never studied or spoken it? In that case they need a sufficient IETS score, etc.
If they have studies English as a second language, here at school, etc it should be suffice with most universities.
If they don't have the english proficiency to study medicine, they will obviously struggle. Two units of english count towards your UAI/ATAR in NSW, so I presume ur an overseas student? In that case IETS, etc is usually required, it is a test to evaluate your english proficiency. You will need to check with the individual medical school/faculty/college you are applying to, as they all have different standards.