Hiriq, also called Chirik (Hebrew: חִירִיקḥiriqIPA:[χiˈʁik]) is a Hebrewniqqudvowel sign represented by a single dot ⟨ִ⟩ underneath the letter. In Modern Hebrew, it indicates the phoneme/i/ which is similar to the "ee" sound in the English word deep and is transliterated with "i". In Yiddish, it indicates the phoneme /ɪ/ which is the same as the "i" sound in the English word skip and is transliterated with "i".
Spelling
When writing with niqqud, the letter yud⟨י⟩ is often written after the letter that carries the Hiriq sign. This is called ḥiriqmale (Hebrew: חִירִיקמָלֵאIPA:[χiˈʁikmaˈle]), meaning "full" (or "plene") hiriq. In writing without niqqud, the letter yud is added more often as a mater lectionis, than in writing with niqqud, The main exception is the "i" vowel in a syllable that ends with shva naḥ. For example the words סִדְרָה (series) and סִדְּרָה (she organized) are pronounced identically in modern Hebrew, but in spelling without niqqud סִדְרָה is written סדרה because there is a shva naḥ on the letter ד, and סִדְּרָה is written סידרה.
These vowels lengths are not manifested in Modern Hebrew. In addition, the short i is usually promoted to a long i in Israeli writing for the sake of disambiguation.
Note: In Yiddish orthography only, the glyph, yud-ḥiriq (יִ), pronounced /i/, can be optionally used, rather than typing yud then ḥiriq (יִ). In Hebrew spelling this would be pronounced /ji/./i/ is written ḥiriq under the previous letter then yud (ִי).