how do I automatically format what I paste

Libre Office 5 Libre Writer using Linux Mint 17.2
When I copy from the internet, for example, and paste into a Writer document, I want what I paste to be in the same format that I am already using in the Writer document.

Test if works for you with Paste special - unformatted text.
[Shift+Ctrl+V] Menu/Edit/Paste special.

Hi

In Writer, the shortcut is Ctrl+Alt+Shift+V

Regards

Thank @pierre, I was thinking on calc.