help - my laptop keyboard is typing the wrong letters!

[HeyMacWey]

I've just cranked up the laptop and when trying to type words each letter is coming up with the wrong ones.
For example
S opens up a new tab on the Internet
D comes up with df5
J comes up as 6j
K comes up as k=
I've pressed fn a few times to see if this helps but doesn't seem to have made much differencd.
It seems to only be the line starting with a s d that seems to bring up the odd characters?
Any ideas? Am posting on my tablet atm, but dd has to finish a presentation this week and needs to use the laptop -arghhhh

Have you tried rebooting it?
Have you got the F Lock key switched on accidentally so keys are defaulting to shortcuts?

Has anyone spilt liquid on it recently? I did to mine last night and today the keys are a bit confused!

No idea what happened there but it seemed to come back to life after pressing all the keys numerous times
For future reference what is the f lock key?