She always pushes the envelope and tries new things.

She pushed the envelope to see how far she could go.

I used push-ins to secure the wires.

I used a push-pin to hang up the poster.

I used a push pin to hang up the poster.

I need to buy some push pins for my bulletin board.

I need to buy some push-pins for my bulletin board.

He pushed through the crowd to get to the front of the line.

He pushes over the table.

He pushed over the table in anger.