What is the guideline when adding ly to a word that end in able or ible?

You're right to ask! It's not always straightforward. Here's the breakdown:

General Rule:

* Add "-ly" directly to the end of words ending in "-able" or "-ible."

Examples:

* Comfortable + ly = Comfortably

* Possible + ly = Possibly

* Responsible + ly = Responsibly

Exceptions:

* Words ending in "-le": If a word ends in "-le," you usually drop the "e" before adding "-ly."

* Example: Gentle + ly = Gently

* Words ending in "-y": If a word ends in "-y," you usually change the "y" to "i" before adding "-ly."

* Example: Easy + ly = Easily

Let's clarify with your specific examples:

* "Able" words: Just add "-ly" directly.

* "Ible" words: Just add "-ly" directly.

Important Note: There are some exceptions, such as "whole" becoming "wholly," but these are generally considered irregular and not part of a larger rule.

Let me know if you have any other word examples you'd like to explore!