The English language/vocabulary/verbal phrases

Of course typos differ from spelling errors and regional variations in spelling and they in turn differ from grammar errors. 

Typos are easy to spot: "teh" instead of "the" and "pwn" instead of "own" are misspellings that could only occur on a typewriter keyboard and are a symptom of typed-conversation where spelling takes a back seat role. In my own writing such typos are frequent because this Acer laptop has a tired and biscuit crumb-filled keyboard so some key-presses fail to register due to the speed in which I type, and the fact that I type faster than my ability to type accurately.

Using "there" when the writer means "their" or "they're" or "your" when they mean "you're" or "yaw" are not typing errors, nor are they a spelling error since all six words pass a spell-checker. They are simply examples of using the wrong word, which makes them grammar errors. Since such homophones are easy to correct and seldom (if ever) lead to ambiguity or misunderstanding, getting all "grammar nazi" over their misused seems silly to me. Grammar errors are not the huge crime against language that some people make them out to be. Though you could argue that they do reflect a deterioration in writing standards, (but not educational standards - people who misuse such words do know the correct word to use), not correcting such mistakes before hitting "post" is more a reflection of impatience and the limitations of time.

Regional variations appeal to me more - I generally write in a British accent so favour (as opposed to favor ) British English spelling, and will type "learnt", "dreamt" and "spelt" instead of "learned", "dreamed" and "spelled" even when the different spellings were at one time pronounced the same and the "-ed" ending was just an adopted spelling convention regardless of how they were pronounced when read out loud. The "-ed" ending can be pronounced "-d", "-id" and "-t" but very seldom "-ed"

Since I find myself sounding the "-ed" ending as "-d" when reading the American spelling (e.g., "spell'd") I suspect that now these regional spelling variants are pronounced that way by those who favour the "-ed" ending... Compare those with "cooked" and "booked", where the common accepted pronunciation is "cook't" and "book't" with a "-t" ending or "waited" or "sated" that are pronounced as "wait-id" and "sate-id".

In both British and American English "learned" meaning 'educated' is of course pronounced "lur-ned" and in British English we would never use "learnt" in that context.