You should consider the expectations of the people to whom you are talking (or for whom you are writing), and also check your horoscope for the day and see if the astrological influences favor informal or formal English.
Idioms are common in informal context, but they are found in all registers of English usage.
Formal English is THE standard English. This is in oppsoition to informal English which is spoken English and includes slang and colloquialisms.
There is no formal slang. Slang is informal language.
Informal
Yes, it is. It is the opposite of the word formal (not formal), and a synonym of casual or unofficial.
Two things to keep in mind when you're deciding whether to use formal or informal English are the occasion and the audience.
informal
Formal: Goeiedag ----> English equivalent: Goodday Informal: Hoi ----> English equivalent: Hi
Formal English is the English written in works like essays, where it's a standardized, formal way to write it, but informal English is what I'm writing in right now, a loose, not very structured way of writing.
Consider the audience you are addressing and the level of formality that is appropriate for the situation. Additionally, be mindful of the tone and style you want to convey through your choice of language.
Please = Alstublieft (formal) and alsjeblieft (informal) Thank you = dank u wel (formal) and dankjewel (informal) Goodbye = tot ziens / dag (formal) and doei (informal)
occasion and audience
like the Russian , English is a formal table style .. but it can be formal or informal depending on the diner if he\she wants to.
It means "You (informal) or you (formal)"
occasion and audience
very informal: Hey informal: Hi more formal: Hello formal: Good morning Good afternoon Good evening
Written grammar typically follows more formal rules and conventions compared to spoken grammar. Spoken grammar tends to be more relaxed and may include slang, contractions, and incomplete sentences. Written grammar also often includes punctuation and sentence structure that may differ from how people naturally speak.