keyboard has suddenly stopped inputting in the correct language

I am new to this forum so I apologise if this has been covered in a previous thread. I am also a new mac user so excuse my lack of knowledge!

My keyboard has suddenly stopped inputting in the correct language which should be British and when I pulled up the on screen keyboard, it appears to be rapidly swithching between British and some other input language.

At the same time that this happened it appears that I can no longer click and drag a file to move it within the same volume, but it automatically copies.

Can anyone please help???

The problem appears to fix itself on a reboot but then the same things start happening shortly after!!

Please help me!!

You are probably accidentally selecting Command - Space which is switching to another language

Go to  menu > System Preferences > Keyboard and mouse

Select the Keyboard shortcuts tab and scroll down to Input menu section, and switch off those 2 shortcuts