In English, an –ing clause is a clause (that is, a part of a sentence) that we use when we want to mention two actions which happen at the same time, or when one action happens before or after the other. These clauses are useful because they allow us to make our sentences much shorter than they would otherwise be. For example: instead of writing ‘Hugh was walking his dog and smoking a cigarette at the same time’, the - ing clause lets us write ‘Hugh was walking his dog, smoking a cigarette’