reflected either, so y can express initial /d͡ʒ/, e.g. yʾm for ǰām 'glass' (while it still expresses /j/ in the learned word yzdt' for yazd 'god'. Some even earlier sound changes are not consistently reflected either, such as the transition of /θ/ to /h/ in some words (in front of /r/ this reflex is due to Parthian influence, since the Middle Persian reflex should have been /s/). In such words, the spelling may have s or, in front of r – t. For example, gāh 'place, time' is spelt gʾs (cf. Old Persian gāθu) and nigāh '(a) look' is spelt nkʾs; šahr 'country, town' is spelt štr' (cf. Avestan xsaθra) and mihr 'Mithra, contract, friendship is spelt mtr'. In contrast, the Manichaean spellings are gʾh, ngʾh, šhr, myhr. Some other words with earlier /θ/ are spelt phonetically in Pahlavi, too: e.g. gēhān gyhʾn 'material world', čihr cyhl 'face'. There are also some other cases where /h/ is spelt /t/ after p: ptwnd for paywand 'connection', and /t/ may also stand for /y/ in that position: ptkʾl for pahikār 'strife'. There are some other phoneme pairs besides /y/ and /d͡ʒ/ that are not distinguished: h (the original Aramaic ḥ) may stand either for /h/ or for /x/ (hm for ham 'also' as well as hl for xar 'donkey'), whereas the use of original Aramaic h is restricted to heterograms (transliterated E in McKenzie's system, e.g. LGLE for pāy 'foot'). Not only /p/, but also the frequent sound /f/ is expressed by the letter p, e.g. plhw' for farrox 'fortunate'. While the original letter r is retained in some words as an expression of the sound /r/, especially in older frequent words and Aramaeograms (e.g. štr' for šahr 'country, town', BRTE for duxt 'daughter'), it is far more common for the letter l to have that function, as in the example plhw' for farrox. In the relatively rare cases where l does express /l/, it can be marked as ɫ. Expression of vowels Like many abjads, the system may express not only consonants, but also some vowels by means of certain consonant signs, the so-called matres lectionis. This is usually limited to long vowels: thus, original ʾ can stand for the vowel /aː/ (e.g. in pʾd for pād), y can stand for /iː/ and /eː/ (e.g.pym for pīm 'pain' and nym for nēm 'half'), and w can stand for /uː/ or /oː/