^ abcdefghThe syllable-final (and also word-final) voiceless obstruents [p, t, k, f, s, χ] are voiced to [b, d, ɡ, v, z, ɣ] (note that [χ] is velar when voiced) when the next syllable (including the next word) begins with a voiced stop and, in case of the fricatives [f, s, χ], also when the next word begins with a vowel (Tiersma (1999:24)).
^ ab[ɡ] and [ɣ] are allophones of a single phoneme /ɣ/. The plosive [ɡ] appears word-initially and syllable-initially (the latter only when stressed), whereas the fricative [ɣ] occurs elsewhere (Hoekstra (2001:86), Sipma (1913:15, 17)).
^In most dialects, /h/ is deleted before [j] and [w] (Tiersma (1999:22)).
^ abcdeThe syllabic nasals [m̩, n̩, ŋ̍] are all phonemically /ən/, whereas the syllabic [l̩, r̩] are phonemically /əl, ər/. To read about their exact distribution, see e.g. Sipma (1913:36). The only sonorants that cannot be syllabic are [ʋ, j].
^ abApart from being the phonetic realization of the phonemes /m, ŋ/, [m, ŋ] occur as allophones of /n/ before, bilabial and velar consonants (Tiersma (1999:24)).
^ abcWord-final /b, d/ are realized as voiceless [p, t] (van der Veen (2001:104)). Note, however, that final /b/ is rare (Tiersma (1999:21)), and that in loanwords from Standard Dutch, final /ɣ/ can also appear, and is also devoiced and retracted to [χ].
^/r/ is silent before other alveolar consonants, i.e. /n, t, d, s, z, l/ (Tiersma (1999:28–29), Keil (2003:8)). An exception to this rule are recent loanwords from Standard Dutch (e.g. sport), which may or may not be pronounced with [r] (Tiersma (1999:29)).
^Intervocalic ⟨d⟩, as well as the sequence ⟨rd⟩ are often rhotacized to /r/ (Tiersma (1999:21)).
^In various pronouns and function words, the initial /d/ becomes voiceless [t] when a voiceless obstruent ends the preceding word (Tiersma (1999:24)).
^ abBoth [ʋ] and [v] can be regarded as allophones of a single phoneme /v/, though [v] is the most common realization. The approximant [ʋ] can appear word-initially, whereas the fricative [v] occurs elsewhere (Keil (2003:7)).
^ abcAmong fricatives, neither the voiced /z/ nor the voiceless /χ/ can occur word-initially (Sipma (1913:16–17)).
^When a sequence of any vowel and /n/ occurs before any continuant besides /h/ (that is, /f, v, ʋ, s, z, r, l, j/), it is realized as a nasalized vowel. When the following consonant is /s/, such a nasalized vowel is also lengthened (but only in stressed syllables (Hoekstra (2001:86))), so that e.g. jûns (phonemically /juns/) is pronounced [jũːs], whereas prins (phonemically /prɪns/) is pronounced [prẽːs]. One exception to this lengthening rule is that when a short vowel precedes the sequence /nst/ in the second person singular verb form (as in winsʋ[vɪ̃st]), it is kept short by most speakers (Tiersma (1999:13)). It is unclear whether the lengthened short monophthongs /ɪ, ø/ (/o/ cannot be lengthened) are phonetically long monophthongs or diphthongs (as it is the case with the oral /eː, øː/), hence the transcription [prẽːs] rather than [prẽĩs].
^/ɑː/ has a phonemic status in the Aastersk dialect (van der Veen (2001:102)).
^/ɪː/ has a phonemic status in the Hindeloopers dialect (van der Veen (2001:102)).
^[øː] is the Hindeloopers realization of /øː/. In other dialects, /øː/ is commonly slightly diphthongal [øy] (van der Veen (2001:102)).
^ abNearly all words with /øː/ are loanwords from Standard Dutch (Visser (1997:17)).
^ abThe open-mid front rounded vowels /œ, œː/ have a phonemic status in the Hindeloopers and Súdwesthoeksk dialects, but not in the standard language (Hoekstra (2001:83), van der Veen (2001:102)).
^ ab[ɵ] and [ɞ] are the southwestern realizations of, respectively, /wo/ and /wa/ (Hoekstra (2003:202), citing Hof (1933:14)).
^[ɔi] is a dialectal realization of /ai/ (Booij (1989:319)).
^In some dialects, /ui/ and /uːi/ are distinct phonemes. In the standard language, however, only /ui/ appears (Tiersma (1999:12)).
^ abPhonetically, /ə/ and /ø/ are quite similar, but the former appears only in unstressed syllables (Tiersma (1999:11)).
^ abcdSome speakers merge the long vowels /iː, uː/ with the centering diphthongs /iə, uə/ (Visser (1997:24)).
^ abThe long close rounded vowels /uː, yː/ do not appear in the dialect of Leeuwarden (van der Veen (2001:102)).
^ abcEven though they pattern with monophthongs, the long close-mid vowels /eː, øː, oː/ are often realized as narrow closing diphthongs ((Visser (1997:22–23), Tiersma (1999:10–11))), and that is how we transcribe them here.
^ abcdefghijThe falling diphthongs [iə, ɪə, oə, uə, yə] alternate with the rising diphthongs [jɪ, jɛ, wa, wo, jø] in the phenomenon called breaking. The [yə−jø] alternation occurs only in the word pair sluere−slurkje (Booij (1989:319)).
Bibliography
Booij, Geert (1989). "On the representation of diphthongs in Frisian". Journal of Linguistics. 25: 319–332. JSTOR4176008.
Hoekstra, Eric (2003). "Frisian. Standardization in progress of a language in decay"(PDF). Germanic Standardizations. Past to Present. Vol. 18. Amsterdam: John Benjamins Publishing Company. pp. 193–209. ISBN 978-90-272-1856-8. Archived(PDF) from the original on 30 March 2017. Retrieved 30 March 2017.
Hoekstra, Jarich (2001). "12. Standard West Frisian". In Munske, Horst Haider; Århammar, Hans (eds.). Handbook of Frisian studies. Tübingen: Max Niemeyer Verlag GmbH. pp. 83–98. ISBN 3-484-73048-X. Retrieved 30 March 2017.
Hof, Jan Jelles (1933). Friesche Dialectgeographie(PDF) (in Dutch). The Hague: Martinus Nijhoff. Archived(PDF) from the original on 7 October 2016. Retrieved 30 March 2017.
Keil, Benjamin (2003). "Frisian phonology"(PDF). Los Angeles: UCLA Department of Linguistics. Archived(PDF) from the original on 4 March 2016. Retrieved 30 March 2017.
Tiersma, Peter Meijes (1999) [First published 1985 in Dordrecht by Foris Publications]. Frisian Reference Grammar (2nd ed.). Leeuwarden: Fryske Akademy. ISBN 90-6171-886-4.
van der Veen, Klaas F. (2001). "13. West Frisian Dialectology and Dialects". In Munske, Horst Haider; Århammar, Hans (eds.). Handbook of Frisian studies. Tübingen: Max Niemeyer Verlag GmbH. pp. 98–116. ISBN 3-484-73048-X. Retrieved 30 March 2017.
Visser, Willem (1997). The Syllable in Frisian(PDF) (PhD). Leiden: Holland Institute of Generative Linguistics. ISBN 90-5569-030-9. Archived(PDF) from the original on 4 March 2016. Retrieved 30 March 2017.
Vissner, Willem. "The labial fricatives". Taalportaal. European Language Resources Association (ELRA). Retrieved 25 March 2019.