May I ask where this conversation is going?
It seems that, rather than being a debate on language, this has taken a different tack. Whether one person likes formality or not is not within the remit of this language forum - it is getting political and personal and we don't do that here.
I'm not a teacher, so please consider any advice I give in that context.
yes. at 3am one can make errors, despite one having been awake for 22 hours.
Try getting a little more sleep - it can do wonders for a jaundiced view.
There is always an appropriate place and time for formal language. For example, in the cockpit of an aircraft, or in the control tower. Several serious accidents have been caused by personnel using informal or non-standard language. That's why beginning in March 2008 The International Civil Aviation Organization has deemed that all aviation personnel must pass an English proficiency exam, and must use standard (which can also be read as "formal") aviation language while communicating via radio.
Formal communication is more about situations than it is about people. There are times when a surgeon will be informal and use colloquialisms, but he won't do so when ordering a set of rib spreaders when he has a patient's chest cracked open on the table.
I'm closing this thread. For those of you who would like to continue discussing the original topic "double spacing", please start a new thread on that topic. For those of you who would like to continue the line of debate that this thread has turned into, please do not start a new thread. Start a new topic.
All the best.