Try this with peanut butter in your mouth

Okay, boys and girls:

I have a sieve full of sifted thistles and a sieve full of unsifted thistles, because I am a thistle sifter.

Let’s go gathering healthy heather with the gay brigade of grand dragoons.

She sifted seven thick-stalked thistles through a strong thick sieve.

In the 19th century, tongue twisters were developed by experts in elocution as a means of mastering proper enunciation.

One practitioner was Lionel Logue, who trained as an elocutionist in his native Australia, and from that work he began taking on students for lessons in “speech correction.” Along with the tongue twisters, Logue was known to draw on other time-honored elocutionary exercises, like having a stutterer shout vowel sounds out of an open window for long periods.

Logue worked with Prince Albert, Duke of York (later King George VI), who was crippled by a stammer that made public speaking a devilish chore.

Logue prescribed a regimen of vocal calisthenics, tongue twisters among them, to improve the mechanics of Bertie’s speech. After the abdication of his brother, Edward VIII, in 1936 opens the throne to Bertie, the therapy has geopolitical consequences, permitting the new king to address the nation in live radio broadcasts on the brink of World War II.

Perhaps there was more involved in his exercises.

Few, if any, of Logue’s linguistic techniques, from the tongue twisters to the word substitutions, would be used by modern speech pathologists, according to Caroline Bowen, an Australian speech therapist who maintains a Web site with information on Logue. But for Logue, the focus on vocal mechanics was most likely just a means to an end, enforcing a bond of trust with his royal patient.

Logue may not have “cured” the stammer, but by instilling a sense of confidence and chipping away at Bertie’s anxieties, he made it possible for the king to untwist his tongue and find his voice at a moment when his country most needed to hear him speak.

How are you? he asked phatically

Know this little words and phrases we use when not trying to actually say anything? How are you? Great!

There's a word for that.

phatic / FATT-ik / adjective

of, relating to, or being speech used for social or emotive purposes rather than for communicating information

To wit:

Joe has a tendency to take even phatic inquiries seriously, so when Kristen asked him how he was feeling, I knew the answer would be much longer than "better, thanks."

"Conversation is also more than the explicit back and forth between individuals asking questions and directly referencing one another. It's about the more subtle back and forth that allow us to keep our connections going. It's about the phatic communication and the gestures, the little updates and the awareness of what's happening in space."

Merriam-Webster:

Phatic was coined in the early 20th century by people who apparently wanted to label a particular quirk of human communication—the tendency to use certain rote phrases (such as the standard greeting "how are you?") merely to establish a social connection without sharing any actual information. It probably won't surprise you, then, to learn that "phatic" derives from the Greek "phatos," a form of the verb "phanai," meaning "to speak." 

Other descendants of "phanai" in English include "apophasis" ("the raising of an issue by claiming not to mention it"), "euphemism," "prophet," and the combining suffix "-phasia" (used to denote a speech disorder). You may also have spotted a similarity to "emphatic," but that turns out to be purely coincidence; "emphatic" traces back to a different Greek verb which means "to show."