How many lines of symmetry does a parallelogram have?

General parallelogram has no lines of symmetry. Some specific types of parallelogram do. See below.

Rhombus is a special type of parallelogram and it has two lines of symmetry - its diagonals.

Rectangle, which is not a square, has two lines of symmetry - two lines going through the midpoints of opposite sides.

Square is a special type of parallelogram with four lines of symmetry - two diagonals and two lines going through the midpoints of opposite sides.