Lucas R. answered 11/23/20
Patient Writing and History Tutor For High School and College
Hi Ari,
A court opinion would use the most formal language. Since court opinions are official legal documents, it's essential that the writing be precise and professional. Perhaps you've heard of the word "legalese," which is used to describe the dense technical language in legal documents.
An instructional manual and newspaper article would both be formal, but not as much as a court opinion. Instructional manuals need to use precise technical vocabulary and clearly describe processes. Newspapers are held to a high factual standard but have some leeway regarding how formal the language is. A letter to your grandmother would be the least formal, since you're on familiar terms with her.
Thanks for your question!