Many operators work on a particular type of data. If the type of the operands differs from the type of the operand, Perl will make copies of the operands and convert them to the needed types. For example, $a + $b will convert a copy of both $a and $b to numbers (unless they are numbers already). This implicit conversion is called coercion.

Besides operators, other syntactic elements coerce their elements: if and while coerce to truth values (Bool), for views things as lists, and so on.