When the suffix -able is added to a verb that ends in -e, the e is usually dropped. Spellings that retain the e are also around, but the simpler forms without the e are recommended:
livable lovable usable movable saleable tradeable
The -eable form is more common in newly formed words (eg saleable, tradeable). When the verb ends in -ce or -ge (eg enhanceable, changeable), the e is retained to show that the c or g is pronounced as a ‘soft’ consonant (ie the c is pronounced as an s, and the g is pronounced as a j).
See also -ible/-able.
