It’s unfortunate for the British that this only seems to apply to the accent, not to BrE grammar, punctuation, and spelling.
For the record, Grammarly.com supports both AmE and BrE.
A run-on sentence walks into a bar it is thirsty.
A sentence fragment into a bar.
Subject pronouns = I/you/we/he/her/they
Object pronouns = me/you/us/him/her/them/whom
Possessive pronouns = my/your/our/his/her/their
Question pronouns = who/what/where/when/why
Relative pronouns = who/that/where/which/whose
“Young Lady, may I please have a word with your mother?” he asked.
“Nah, she ain’t home,” the girl replied.
Taken aback, the man scolded the little girl: “Young lady, where’s your grammar?”
“She’s upstairs taking a bath.”