Difference between informal and formal essay:
Informal: May use colloquial words (What we normally say)
Formal: No using colloquial words( more formal)
Informal: May use contractions and abbreviated words which are colloquial.
Formal: Avoid using abbreviated words, write full version of the words. No contractions, write out full words.
Informal: May use first, second, or third person.
Formal: Only in third person
Informal: May use imperative voice and active voice
Formal: Avoid imperative voice and passive voice
Informal: May use short and simple sentences.
Formal: Longer and more complex sentences are preferred
Informal essays are more personal than the formal essays. When writing a informal essay, writer often write in a conversition style but formal essays cannot. Informal essays are more relaxed style to show writer' s opinion more enjoyment to write and less worries for the tense, words to use of the essay.