My Grandfather, AKA "The Grandfather Passage", is one of the
most common standard reading passages used to test an
individual's ability to produce connected speech. If you are
having a thorough speech evaluation, one of the last things the
evaluator will do is hand you a paper containing block of text
for you to read. There's a good chance that that text will be My
Grandfather.  It was designed to contain almost all the English
phonemes (by my count it's missing ʒ and the glottal stop). In
this it is closely related to Arthur the Rat, a block of text
used for studying accents and dialects. There are minor
variations, but it goes something like this:  You wish to know
all about my grandfather. Well, he is nearly 93 years old; He
dresses himself in an ancient, black frock coat, usually minus
several buttons; yet he still thinks as swiftly as ever. A long,
flowing beard clings to his chin, giving those who observe him a
pronounced feeling of the utmost respect. When he speaks his
voice is just a bit cracked and