Fer ferr
This one is tricky – we have looked at it before, but it is worth looking at it over and over as it is kept for year 6 due to its difficulty.
Think: Where is the stress? If the stress is on the fer, double the r. It will sound like fer. If the stress is not on fer, keep it as a single r: it will sound like fr when the word is said quickly.
Buffering
Circumference
transferring
Deferrable
Refereed
Suffered
Different
Conferring
Preferred
Buffered
*Again, see if you can find lots of other words with fer and ferr in as this will help you see the rule consistently used and help secure the pattern.