As initialisms the difference between mo and fa

is that mo is modus operandi while FA is football Association esp English Football Association see also Scottish FA and Welsh FA.

As nouns the difference between mo and fa

is that mo is month while fa is a syllable used in solfège to represent the fourth note of a major scale.

As an abbreviation MO

is missouri, a state of the United States of America.

As a proper noun Mo

is abbreviation of Missouri|lang=en.

As an adverb mo

is to a greater degree.

As an adjective mo

is greater in amount, quantity, or number (of discrete objects, as opposed to more, which was applied to subtances)