In conservative speech, "l" is realized as a tapped "r", however in general cases it is realized as "l", perhaps in due part to the influence of English. Word initially, "b" is optional for /m/, though "b" is more commonly realized. The glottal sonorant /h/ assimilates to the nasality of the following segment, but retains its voicelessness. When following "i" or "e" or preceding "ch", /h/ may be realized as an alveopalatal fricative. Vowel sequences across morpheme boundaries can be quite varied, but short vowels cannot appear alone in the morpheme: V:V (long+short), V:V: (long+long) and diphthong+V (short). Word finally, only "a" (in a diphthong), "o", and "u" (allomorphs of the plural suffix) can occur after a long vowel. A wide variety of consonant clusters can occur in Crow. All consonants except for /h/ can be geminated. Voiced labials and dentals (phonemic "m" and "n", allophones "b", "m", "w" and "d", "n", "l") are resistant to clustering. Because they only occur intervocallically, "l" and "w" do not occur in clusters. The plosive allophones "b" and "d" only occur in clusters as the second consonant and only at morpheme boundaries. The nasal allophones "m" and "n" can only occur with each other with the exception of "nm", or occur with "h" at a morpheme boundary. Clusters in general occur at morphemic boundaries. Some morphemic constraints:  Stress in Crow is phonemic. The position of the stress in the stem is determined lexically. Virtually all noun and verb stems have an inherent stress. In word initial syllables, accented short vowels in a word initial syllable are generally followed by a consonant cluster, while accented long vowels are generally followed by a single consonant. Stress can fall on short vowels as well as long vowels and may fall on either mora of a long vowel. With diphthongs, either the long vowel or the offglide may bear the stress. Stress helps predict the tones of all the vowels in a word: stressed vowels are high in pitch; all vowels following the stressed vowel are low in pitch; all short vowels preceding the stressed vowel are low in pitch; all long vowels preceding the stressed vowel are high in pitch; short vowels occurring between a long vowel and the accented vowel assimilate to a high pitch.