Ka (Bengali)
The Bengali letter ক is derived from the Siddhaṃ 
, and is marked by a similar horizontal head line, but less geometric shape, than its Devanagari counterpart, क. The inherent vowel of Bengali consonant letters is /ɔ/, so the bare letter ক will sometimes be transliterated as "ko" instead of "ka". Adding okar, the "o" vowel mark, কো, gives a reading of /ko/.
Like all Indic consonants, ক can be modified by marks to indicate another (or no) vowel than its inherent "a".
ক in Bengali-using languages
ক is used as a basic consonant character in all of the major Bengali script orthographies, including Bengali and Assamese. It is also used with a nukta, ক়, for foreign borrowings of /q/.
Conjuncts with ক
Bengali ক exhibits conjunct ligatures, as is common in Indic scripts, with a tendency towards stacked ligatures.[1]
- ক্ + ষ [ʃ] gives us the irregular kʃa ligature. The conjunct functions as an independent letter in the Assamese orthography, with a different pronunciation than the Bengali ligature of ক্ + ষ.
- ক্ + স [s] preserves the ক, but reduces the স, giving
- ক্ + ক results in a stacked conjunct
- ঙ্ [ŋ] + ক also gives a stacked conjuct with a somewhat irregular form
- ক্ + র [ɾ] is a fully ligated (irregular) conjunct
