This language consists of strings with a b, followed by at least two a's, followed by an exclamation point. The set of operators that allows us to say things like "some number of as" are based on the asterisk or *, commonly called the Kleene * (gen-Kleene * erally pronounced "cleany star"). The Kleene star means "zero or more occurrences of the immediately previous character or regular expression". So /a*/ means "any string of zero or more as". This will match a or aaaaaa, but it will also match Off Minor since the string Off Minor has zero a's. So the regular expression for matching one or more a is /aa*/, meaning one a followed by zero or more as. More complex patterns can also be repeated. So /[ab]*/ means "zero or more a's or b's" (not "zero or more right square braces"). This will match strings like aaaa or ababab or bbbb.