VC - The words in this column have a base word that ends in a Vowel Consonant pattern. Notice that ALL of these words have the final consonant doubled before adding the suffix. This keeps the short vowel sound.
hopped
planned
grabbed
nodded
stepped
dropped
VCe - all of these words have a base word that ends with a Vowel, Consonant, silent e pattern. Notice all of these words have a long vowel sound.
hoped
saved
closed
liked
lived
named
VVC - all of these words have a base word that ends with a Vowel, Vowel, Consonant pattern. Notice that all of these words also have a long vowel sound.
joined
waited
seemed
shouted
VCC - all of these words have a base word that ends with a Vowel, Consonant, Consonant pattern. Notice that all of these words have a short vowel sound, and since they already end in 2 consonants, there is no need to double a consonant before adding a suffix.
acted
wanted
helped
started
hunted
passed
called
Oddball - there is one word, that appears to go in the VC column, but does not have a doubled consonant before adding the suffix.
mixed
The x is not doubled because we do not find an xx pattern in English words (with the exception of the company name Exxon.)