People who write "your" when they mean "you're" (as in "you are"). I think this is possibly the single most common grammatical error, among people of all ages.
However, the one which annoys me most is "should of" or "would of" instead of "should have" and "would have".
I disagree! In both those cases, the actual words are in fact spelt correctly.....it is incorrect usage of the word or phrase, which in my book makes these grammatical errors.
Good day, Miranda.
The actual words are
misspelled, because the actual words are being used. People just choose the wrong spelling. You've yourself have noted just how common these errors are.
English has strong and weak pronunciations for a number of very common words. You've provided some examples of the more common ones. These mistakes happen to everyone at one time or another, to some more than others.
They happen to all of us all the time when we speak.
Do you think that when people make these slip ups they actually don't understand the grammar? When we write things like, "He shudda"; "she wuddav", we are also writing the sounds we make in speech.