Example of Colloquial English:
Colloquial english is like whatever, its how people normally talk like, not how they write. if you are writing colloquially just say something that uses the grammar and words you normally use, you know.
Example of Formal English:
Formal English is format typically reserved for academic or journalistic writing. It typically follows a more strictly regimented grammar structure.\////////%/\/\/\/
Due to the differences in accents and pronunciation it makes it a bit difficult. They also have certain words that are different for the others. Britain may say fringe v.s how Americans would say bangs.