The Rule:
If a word ends in a silent "e" and the ending you're adding starts with a consonant, drop the "e" before adding "-able".
Examples:
* love + able = lovable
* care + able = careable (though "careful" is more common)
* move + able = movable
* manage + able = manageable
Exceptions:
* Words ending in "ge" or "ce" do not drop the "e" before "-able":
* change + able = changeable
* notice + able = noticeable
* Words ending in "-ie" usually change the "ie" to "y" before adding "-able":
* tie + able = tyable
Let me know if you'd like to practice some more examples!