[Grammar] Double SS

[crazyaboutenglish]

Hi, can anyone please tell me if there is a rule to help me know when to put a double ss in a word like possible or passive.

thanks

 

[Grumpy]

I don't think there is such a rule. Sorry. There are rules for inserting an extra consonant when a word ends in "ing" or "ed", so that "rub" becomes "rubbed", and "run" becomes "running"; but the examples you quote are words in their own right.

 

[crazyaboutenglish]

Thank you! I'll find a list and start to memorise