Which letter to the editor is more formal?
I'm writing because I'm fed up about our library not staying open like it used to. I am writing to express my dissatisfaction with the library's reduced hours.
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 second letter to the editor is more formal. It uses more elevated language (writing to express my dissatisfaction, reduced hours). The other letter to the editor uses contractions (I'm) and slang (fed up).