Just select all the text you want to quote from their post, and a button will appear on top of the select text that says “Quote”. Click on that and the selected text will appear in your reply formatted as a quote.
It will appear in the reply editor in the following format:
[quote="Huguette, post:3, topic:100"] One can only be aware of “what is”. [/quote]
and will look like this in the preview pane:
You can repeat this process as many times as you wish to quote multiple selections, either from a single post or from many different ones.