The stop + spirant clusters ʔθ, ʔs, and ʔh all show up word initially and word medially, whereas the stop + semivowel clusters dw and gw only show up word medially [REF].
An interesting analysis of the Chiwere language has shown that the spirant + stop consonant cluster hg is the more commonly used pronunciation of the spirant + stop cluster θg and that the hg cluster may be replacing the θg altogether [REF].