Answer:
True
Explanation:
Parallelogram: A parallelogram is 4-sided shape that has parallel opposite sides
Square: A square is 4-sided shape where all sides are congruent and has 4 right angles. A square also has 2 pairs of opposite parallel sides.
Based on these definitions, we can see that not ALL parallelograms can be squares because a parallelogram can have no right angles, or can have all 4 angles be right angles.
All squares have to be parallelograms though because a square and a parallelogram both have 2 pairs of opposite parallel sides.
Hope this helps :)