Which holiday greeting is more formal?
May your Thanksgiving be filled with family and fun! I hope that you and your gang have a blast this Thanksgiving!
Informal writing is typically used in casual situations or when communicating with someone you know well. Informal language often expresses familiarity and tends to sound more like speech. It uses more conversational language, such as slang, idioms, abbreviations, imprecise language, and contractions.
Formal writing is typically used in academic and business writing or when writing directly to an authority figure. It tends to be more courteous and impersonal, avoiding overly familiar or conversational language.
Compare the following sentences.
Informal: Yeah, ostriches can't fly, but I think they're awesome.
More formal: Ostriches may be flightless, but they're remarkable runners.
Most formal: Though flightless, ostriches are remarkable runners.
The first holiday greeting is more formal. It uses more ceremonious language (may your Thanksgiving be filled). The other holiday greeting uses slang (your gang, have a blast) and sounds more casual.