The student may be working with a tutor who helps develop skills of fluent expression in written English. However coursework essays may still have errors in syntax and grammar. It is important to be clear whether the assessment criteria demand correct grammar as well as knowledge and understanding of the subject.
Deaf students may need further clarification about what feedback comments mean. Give students the opportunity to come and see you for this purpose. Remember that deaf students who are BSL users may need to book an interpreter, therefore do not take it for granted that they can simply come and speak to you at the end of a lecture or seminar as the interpreter may not be available.
You may receive advice that exam scripts from certain deaf students (e.g. those whose first language is BSL) should be marked for content and understanding and not for structure, correct syntax or grammar.
The RNID provides a factsheet about marking deaf students' work in the Information and Resources section.