This is a list of tetragraphs in the Latin script. These are most common in Irish orthography. For Cyrillic tetragraphs, see tetragraph#Cyrillic script.

Irish tetragraphs [link]

Used between two velarized ("broad") consonants:

⟨adha⟩ and ⟨agha⟩ are used for [əi̯] (in Donegal, [eː]).

⟨abha⟩, ⟨amha⟩, ⟨obha⟩, ⟨odha⟩, ⟨ogha⟩ are used for [əu̯] (in Donegal, [oː]).

⟨omha⟩ is used for [oː].

Used between two platalized ("slender") consonants:

⟨eidh⟩ and ⟨eigh⟩ are used for [əi̯].

Used between a broad and a slender consonant:

⟨aidh⟩ and ⟨aigh⟩ are used for [əi̯] (in Donegal, [eː]).

⟨oidh⟩ and ⟨oigh⟩ are used for [əi̯].

Used between a slender and a broad consonant:

⟨eabh⟩ and ⟨eamh⟩ are used for [əu̯] (in Donegal, [oː]).

⟨eadh⟩ is used for [əi̯] (in Donegal, [eː]) between a slender and a broad consonant, or for an unstressed [ə] at the end of a word.

Other languages [link]

⟨chth⟩ is used for an initial sound /θ/ in English words of Greek origin such as chthonian. When not initial, it is pronounced /kθ/, as in autochthonous.

⟨dcg’⟩ was used in the 1987 orthography of Juǀʼhoansi for the click [ᶢǀ^ʢ].

⟨dçg’⟩ was used in the 1987 orthography of Juǀʼhoansi for the click [ᶢǂ^ʢ].

⟨ddzs⟩ is a long variant of Hungarian dzs. It is only found in suffixed words, such as bridzs + dzsel → briddzsel "with the bridge game"; otherwise the sound [dːʒ] is written ⟨dzs⟩ like [dʒ].

⟨dqg’⟩ was used in the 1987 orthography of Juǀʼhoansi for the click [ᶢǃ^ʢ].

⟨dsch⟩ is used in German to write the sound [dʒ].

⟨dxg’⟩ was used in the 1987 orthography of Juǀʼhoansi for the click [ᶢǁ^ʢ].

⟨eeuw⟩ and ⟨ieuw⟩ are used in Dutch for the sounds [eːu̯] and [iːu̯]. ⟨Uw⟩ alone stands for [yːu̯], so these sequences are not predictable.

⟨gqx’⟩ is used in the practical orthography of the Taa language, where it represents the prevoiced affricate [ɢqχʼ].

⟨illi⟩ is used in French to write the sound [j] in a few words such as médaillier [medaje].

⟨kngw⟩ is used for /ᵏŋʷ/ in Arrernte.

⟨ndlh⟩ is found in the Romanized Popular Alphabet used to write Hmong, representing the prenasalized aspirated consonant [ndˡʱ].

⟨ng’w⟩ is used for [ŋʷ] in Swahili-based alphabets.

⟨nplh⟩ is found in the Romanized Popular Alphabet used to write Hmong, representing the prenasalized aspirated consonant [mbˡʱ].

⟨ntsh⟩ is found in the Romanized Popular Alphabet used to write Hmong, representing the prenasalized aspirated consonant [ɳɖʐʱ].

⟨ntxh⟩ is found in the Romanized Popular Alphabet used to write Hmong, representing the prenasalized aspirated consonant [ndzʱ].

⟨nyng⟩ is used in Yanyuwa to write a pre-velar nasal, [ŋ̟].

⟨phth⟩ is read as an initial sound /θ/ or /fθ/ in English words of Greek origin such as phthisis. When not initial, it is usually pronounced /fθ/, as in naphthol., although sometimes /pθ/ can be heard.^[1]

⟨rtnw⟩ is used for /^ʈɳʷ/ in Arrernte.

⟨s-c⟩ and ⟨s-cc⟩ are used in Piedmontese for the sequence /stʃ/.

⟨s-ch⟩ is used in the Puter dialect of the Romansh language (spoken in the Upper Engadin area in Switzerland) for the sequence /ʃtɕ/. While the orthography using this tetragraph is no longer official, it is retained in place names like S-chanf.

⟨s-g⟩ and ⟨s-gg⟩ are used in Piedmontese for the sequence /zdʒ/.

⟨thsh⟩ is used in Xhosa to write the sound [tʃʰ]. It is often replaced with the ambiguous trigraph ⟨tsh⟩.

⟨thnw⟩ and ⟨tnhw⟩ are used for /ᵗ̪n̪ʷ/ in Arrernte.

⟨tnyw⟩ is used for /ᶜɲʷ/ in Arrernte.

⟨tsch⟩ is used in German to write the sound [tʃ]. (See also ⟨tzsch⟩.)

⟨zsch⟩ is used for [tʃ] in a few German names such as Zschopau.

References [link]