Omitting the subject in writing?

Question

I wonder whether it is formal to omit the subject in writing. Must all sentences always have a subject when I'm writing an English test? Ìs it colloquial and reserved to speech?

Answer 1

When you say "test", I'm not sure if you mean a standardized test, or an in-class writing. However, all sentences require subjects except for imperative sentences ("Get out!"). Of course, for fiction, authors use this style all the time to show natural dialog or a colloquial style. And indeed in an email or business memo, for a bulleted list, one might write:

*review prior report

*provide new comments by Monday

again, a type of command. But if you're being tested on formal grammar, you must be able to supply or identify a subject for any sentence, or explain why it doesn't exist.