Yaa
The /y/ consonant and the long /ii/ vowel.
Sound
Yaa has dual function. As a consonant, it is /j/ — the "y" of English yes, yard. As a long vowel, it is /iː/ — the long "ee" of English see, tree. Which value applies depends on its role in the syllable: it is /iː/ when carrying the long-i value (typically after a short i), and /j/ otherwise.
Yaa is also one of the carriers of hamza in writing (ئ), where a glottal stop sits on a yaa-shape (often dotless in that role).
Egyptian variation: in Egyptian Arabic typography and in many Egyptian books and newspapers, the dotless final ى (alif maqSuura) is used at the end of words where Modern Standard Arabic would use either yaa or alif. So a final yaa-shape without dots is genuinely ambiguous in Egyptian-published texts: it might be /iː/, /j/, or /aː/ depending on the word. This is a real source of variation that learners trip over when moving between Egyptian and Levantine or Gulf typography.
Forms
Connecting behavior
Yaa connects on both sides.
Easy to confuse with
Alif maqSuura (ى). Same shape as final yaa, but no dots underneath. Alif maqSuura represents /aː/ at the end of certain words — most famously the preposition عَلى (ʿalaa, "on") and the name مُصطَفى (Mustafa). The two dots beneath are what mark a final shape as yaa rather than alif maqSuura.
In Egyptian texts the dots are routinely omitted even where MSA convention would require them, so Egyptian readers learn to disambiguate by context.
Examples in common words
A note on handwriting
The two dots below the final and isolated forms are critical in MSA, but in casual Egyptian handwriting they are routinely dropped, merging the letter visually with alif maqSuura. The shape itself — a wide curve that dips below the baseline and sweeps right — is one of the more graceful in the alphabet and is drawn in a single motion. In initial and medial position, yaa's body sits on the line as a small tooth, with the two dots underneath remaining the identifying mark (distinguishing it from baa, taa, thaa, and noon).