Shibboleths

In Mandarin Chinese, the sentence sì shì sì, shí shì shí, shísì shì shísì, sìshí shì sìshí (四是四，十是十，十四是十四，四十是四十; four is four, ten is ten, fourteen is fourteen, forty is forty) is used to distinguish between native speakers of northern varieties of Mandarin from northern China, and native speakers of other Chinese varieties from central and southern China, including Jianghuai Mandarin, Southwestern Mandarin, Cantonese, Wu, Min Nan, and so forth, most of which lacks the retroflex consonant sh /ʂ/.

A Czech or Slovak shibboleth is Strč prst skrz krk, meaning "stick the finger through the throat". This is usually used to verify whether someone is drunk or not. It is also a sentence made only of consonants.

Krai kai kai gai (ใครขายไข่ไก่) or Kai kai kai: This phrase is used to teach Thai children the subtleties of their tonal language. When each word is pronounced with the proper tone, the phrase means, "Who sells chicken eggs?"
Rødgrød med fløde [ˈʁøðgʁøːˀð mɛð ˈfløːðɛ]: The definitive test of one's mastery of the Danish language. No non-native is likely to pronounce the sentence (which means 'mashed strawberries with cream' in English) correctly due to the overwhelming amount of Danish phonemes.
Rugbrød : Danish for Rye bread, almost impossible for non-scandinavians to pronounce due to the "soft" g and d and the Scandinavian letter ø.


Shibboleths used in war and persecution

Ciciri (Chickpeas): This was used by native Sicilians to ferret out Norman French soldiers in the late 1200s during an uprising (Sicilian Vespers) against Angevin rule. The Italian soft c /tʃ/ was (and is still) difficult for the French to pronounce.
Schild en vriend: On May 18, 1302, the people of Bruges killed the French occupants during a nocturnal surprise attack. According to a famous legend, they asked every suspicious person to say "schild en vriend" (shield and friend). The Flemings pronounced it with a separate "s" /s/ and "ch" /x/" (see also "Scheveningen", later in this section); the French "sk". That way they could easily ferret out the French. This day is known as the Bruges Matins or Brugse Metten. The problem with this legend is that even today some inhabitants of Flanders (particularly around Kortrijk, where the famous Battle of the Golden Spurs took place subsequently), also pronounce "sk" and many of the French supporters in Bruges spoke Dutch as their mother tongue. That's why it's sometimes said that the words must have been "'s Gilden Vriend" meaning "Friend of the Guild". The combination of the 's and the g in Gilden would create /sx/ in both Brugge and Kortrijk. Like the name of the massacre, the story may have been influenced by the Sicilian uprising mentioned below.
Soczewica, koło, miele, młyn ("Lentil, wheel, grinds [verb], mill)": In 1312, Wladislaus the Short quelled a rebellion in Kraków, populated mostly by Silesian, German and Czech citizens. Anyone over the age of 7 who couldn't pronounce these four Polish words was put to death, ejected from the city or had his property confiscated. 'Ł' (velarized alveolar approximant) and initial voiceless /s/ are both difficult to pronounce for Germans.
The Catalan sentence Setze jutges d'un jutjat mengen fetge d'un penjat [ˈsɛd͡zə ˈʒud͡ʒəz ðuɲ ʒu'd͡ʒat 'meɲʒəɱ 'fed͡ʒə ðum pəɲ'ʒat] ("Sixteen judges of a court eat the liver of a hanged man") was used by the defenders of Barcelona to distinguish the besieging ethnic Spanish[1](native Castilian speakers) during the War of Spanish Succession(1701–1714). The same device is also mentioned as having been used much earlier, by the 14th century Almogàver mercenaries of the Catalan Company, active in Greece, to distinguish Turks [2] from Catalans. These other groups found it difficult to pronounce the /z/, /ʒ/ and /d͡ʒ/ sounds. Oral tradition has added several different endings to the sentence.
Bûter, brea, en griene tsiis; wa't dat net sizze kin, is gjin oprjochte Fries (example (help· info)) means "Butter, bread and green cheese, who cannot say that is no real Frisian" was used by the Frisian Grutte Pier during a Frisian-Holland war (1515-1519). Ships whose crew could not pronounce this properly were usually plundered.
In the Paraguay War (1864–1870), Brazilian soldiers would identify Paraguayan citizens by having them say the word pão, meaning "bread". Non-native Portuguese speakers have great difficulty making the ão sound — instead, they would say pan or pao (without the nasalization indicated by the tilde).
During the Cuban War of Independence, prisoners caught by the insurgents were asked to pronounce the word "garbanzo" ([gaɾˈbanθo] in Castilian Spanish). Cubans pronounced the /ɾ/ as /l/, and /θ/ as /s/, resulting [galˈbanso]. Therefore they were considered as traitors.
Yksi: Finnish for "one", used by the White Guard to separate Russians from Finns in the Finnish Civil War during the invasion of Tampere. Many of the Russians caught had changed to civilian clothing, so suspected people were rounded up, even from hospitals, and asked to say "yksi". If the prisoner pronounced "juksi", mistaking the front vowel 'y' for an iotated 'u', he was considered a Russian foreign fighter and was shot on the spot. The problem was that any Slav or Balt, Communist or not, was killed, including some volunteers of the White Guard. (Source: Heikki Ylikangas, Tie Tampereelle)
Paljanytsja: Ukrainian word "паляниця" ([pɐlʲɐˈnɪʦʲɐ]) was used by soldiers of Makhno troops to identify Russians of Bolshevik food-troops, who were sent into Ukraine to expropriate food. Russians pronounce the word approximately as [pəlʲɪnʲiʦə]. The word "paljanytsja" was also used during World War II by Ukrainian nationalists to identify Russians..
15円 50銭 (jū-go-en, go-jū-sen) and がぎぐげご (gagigugego) were used in Japan after the 1923 Great Kanto earthquake to search for Koreans, who were killed. They were accused of poisoning wells.
Ba, bi, bu, be, bo Japanese used this syllabary group to detect Korean spies. Koreans would pronounce the syllables unvoiced, pa, pi, pu, pe, po.
The Spanish word perejil (parsley) was used as a shibboleth by Dominican Republic strongman Trujillo against Haitian immigrants at Río Massacre. See [5].
Scheveningen (example (help· info)): Dutch people pronounce this word with separate "s" /s/ and "ch" /x/, while German people pronounce sch as [ʃ] (IPA). The Dutch Resistance used this to ferret out Nazi spies during World War II.
Höyryjyrä: (IPA [høyryjyræ], Engl. "Steam Roller") Finnish soldiers in World War II used this as a password, as only a native Finnish speaker could properly say this word, which contains the Finnish front vowels Ö, Y, and Ä in combination with the rolled R used in Finnish. The leading H /h/ is particularly hard for Russian speakers, since the same sound does not exist in Russian; analogous Russian sounds /g/, /ɦ/ and /x/ are distinguishable.
During the Battle of Normandy in the Second World War, the American forces used the challenge-response codes "Flash" - "Thunder" - "Welcome". The last response was used to identify the challenger as a native English speaker (and therefore not an enemy), whereas the German enemy would pronounce it as "Velcome". This caused problems for German Jews serving in the U.S. Army.
Similarly during Operation Chariot the British raiders used the challenge "War Weapons Week" and the countersign "Welmouth", likewise unpronounceable by most Germans.
Woolloomooloo was used by Australian soldiers in the Pacific Theatre during the Second World War to identify themselves when approaching a camp.
During World War II the Nazis made a test to root out unidentified Jews who were amongst them by serving tea to a group of people, and placing sugar cubes on the table. The Jews would supposedly place the sugar cube in their mouths, while the ethnic Germans would place the cube into the tea. This is an example of a shibboleth through action.
During the Israeli War of Independence, Israeli army passwords were often chosen to contain 'p' sounds, which native speakers of Arabic can rarely pronounce properly.
During the Sumgait Pogrom a common method of seeking out who was Armenian in the vehicles was by asking them to pronounce the Azeri word for hazelnut, fundukh. Armenians however pronounced the first letter with a "p", instantly giving away their identity.

Humorous shibboleths
Olin seitsemän vuotta sedälläni kodossa renkinä (Finnish for "I spent seven years at my uncle's home as a servant"). This is to tease Eastern Tavastians, who pronounce 'd' as 'l'. It becomes Olin seitsemän vuotta selälläni kolossa renkinä, which means "I spent seven years a servant in a hole, lying on my back" — certain connotations of being a sex slave.
Kurri etsi jarrua murkkukasasta ("Kurri looked for a brake in the ant pile."). The Finnish phoneme rolled R [r] in general is considered a "shibboleth" between standard Finnish and various types of speech defects. Small children usually learn the phoneme /r/ last, using /l/ instead. Older children can trick them to say "kulli etsi Jallua mulkkukasasta", "The cock looked for a Jallu (porn magazine) in a pile of dicks."
Germany: Oachkatzlschwoaf is used to tell true Bavarians and Austrians from non-natives, mostly northern Germans. Eekkattensteert is jokingly used by northern Germans to expose Bavarians. Both words mean "squirrel tail".
The German word "Streichholzschächtelchen" (small matchbox) is also used to jokingly identify non-native German speakers.

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