Copy and pasting -- how to toggle between strip formatting and keep formatting

Hello,

I would like to know an easy way of toggling between copy and pasting where you keep the original formatting of what you are copying, and then also copying and pasting where you the format of what you are pasting changes, to match the style of the document.

I am a writer and I often make documents which need to use both equally, so I would love to know a quicker way of doing this.

I use pages.

Thanks

Ruth