Y4 English Suffixes Part I

Question:
What is the rule for adding a suffix to a root word ending in 2 consonants?
Question:
What is the rule for adding a suffix to a root word that has a short vowel followed by a consonant?
Question:
What is the rule for adding a suffix to a root word ending in a consonant followed by an "e"?
Question:
What is the rule for adding a suffix to a root word ending in a consonant followed by a "y"?
Question:
Adding "-ing" to a word ending in "y" is an exception to the rule. Add "-ing" to Cry and Ski - what do you get?