Mac Book Air - Pages - Automatic capital letters at beginning of sentences

I am getting frustrated that I can't work out how to make my computer put capital letters at beginning of sentences and after full stops. I write a lot of essays using Pages so it is a pain having to re-write words and manually putting it in. This may sound lazy but it is something I'm used to happening on other Microsoft computers but can't seem to find a way of changing the settings on here.

Please could someone point me in the right direction

Kind regards

Nic