Ds1 is currently having the -ing rules explained to him (and tested). If there's an 'e' you remove the 'e' and add -ing. If there's two consonants (cc) then you just add -ing. If there's a vowel consonant (vc) then you have to double the consonant and then add -ing. Fair enough.
We've had:
shop shopping
talk talking
write writing
etc.
But in this week's group (and no indication that there are words that break this rule) there is:
speak speaking
shout shouting
So why isn't it speakking and shoutting? Is there a rule they missed off or are these just exceptions designed to trip up the unsuspecting 7 year old?