The Bengali letter খ is derived from the Siddhaṃ , and is marked by the lack of a horizontal head line, unlike its Devanagari counterpart, ख. The inherent vowel of Bengali consonant letters is /ɔ/, so the bare letter খ will sometimes be transliterated as "kho" instead of "kha". Adding okar, the "o" vowel mark, খো, gives a reading of /kho/.
Like all Indic consonants, খ can be modified by marks to indicate another (or no) vowel than its inherent "a".
খ in Bengali-using languages
Conjuncts with খ
Bengali খ does not exhibit any irregular conjunct ligatures, beyond adding the standard trailing forms of ব, য ya-phala, and র ra-phala, and the leading repha form of র.
- খ্ + ব [kh+ba] gives us the ligature
- খ্ + য [kh+ya] gives us the ligature
- খ্ + র [kh+ra] gives us the ligature
- while র্ + খ [r+kha] gives us the ligature
- "The Bengali Alphabet" (PDF).