When you use it
Use this when you describe a noun with who, whom, whose, which, that, where or when, and must decide which type of clause it is. A defining clause limits the noun, and a non-defining clause only adds extra information.
Watch out
Test it by removing the clause. If the meaning stays the same, it is non-defining (Addis Ababa University, which is entirely face to face, has main offices at Sidist Kilo). If the meaning changes or the sentence is incomplete, it is defining (The student who sits in the back asks a lot of questions).
Drafted from Grade 11 English, pages 33-63, then checked twice before it went up

