Pseudo-fricatives
- voiceless glottal transition, as in English hat
- breathy-voiced glottal transition
In many languages, such as English, the glottal "fricatives" are unaccompanied phonation states of the glottis, without any accompanying manner, fricative or otherwise. However, in languages such as Arabic, they are true fricatives.
In addition, is usually called a "voiceless labial-velar fricative", but it is actually an approximant. True doubly-articulated fricatives may not occur in any language; but see voiceless palatal-velar fricative for a putative (and rather controversial) example.
Read more about this topic: Fricative Consonant