There are so many exceptions to this rule that you may want to learn to spell the words that end in o individually. Most verbs take the suffix s in the third-person singular. Verbs ending in s, z, x, sh , or ch take the suffix es to form the third-person singular. Verbs ending in o preceded by a vowel add only s to form the third-person singular. Verbs ending in y preceded by a consonant change the y to i , and add es to form the third-person singular.
Some verbs ending in o preceded by a consonant add es to form the third-person singular.
When a word ending in e is preceded by a consonant, the e dropped when a suffix beginning with a vowel follows. When a suffix beginning with a consonant joins a word, keep the e . Some exceptions are abridg ment , acknowledg ment , and judg ment . These spellings are every bit as correct as abridgement, acknowledgement, and judgement. Words ending in y preceded by a vowel retain the y before a suffix.