to be neutralized. Sonorants Nasals and laterals The three nasal phonemes—, , and —maintain their contrast when in syllable-initial position (e.g. cama 'bed', cana 'grey hair', caña 'sugar cane'). In syllable-final position, this three-way contrast is lost as nasals assimilate to the place of articulation of the following consonant—even across a word boundary; or, if a nasal is followed by a pause rather than a consonant, it is realized for most speakers as alveolar (though in Caribbean varieties, this may instead be or an omitted nasal with nasalization of the preceding vowel). Thus is realized as before labial consonants, and as before velar ones. Additionally, word-final and in stand-alone loanwords or proper nouns are substituted with . Similarly, assimilates to the place of articulation of a following coronal consonant, i.e. a consonant that is interdental, dental, alveolar, or palatal. In dialects that maintain the use of , there is no contrast between and in coda position, and syllable-final appears only as an allophone of in rapid speech. Rhotics The alveolar trill and the alveolar flap are in phonemic contrast word-internally between vowels (as in carro 'car' vs caro 'expensive'), but are otherwise in complementary distribution as long as syllable structure is taken into account: the tap occurs after any syllable-initial consonant, while the trill occurs after any syllable-final consonant. Only the tap can occur after a word-initial obstruent consonant as part of a cluster (e.g. tres 'three', frío 'cold'). Only the trill can occur word-initially (e.g. rey 'king') or at the start of a word-internal syllable when the preceding syllable ends with a consonant, which is always the case after , , (e.g. alrededor, enriquecer, Israel). After the word-medial obstruent consonants , , , either a tap or trill can be found depending on whether the rhotic consonant is pronounced in the same syllable as the preceding obstruent (forming a complex onset cluster) or in a separate syllable (with the obstruent in the coda of the preceding syllable). For example, the words subrayar, ciudadrealeño, postromántico have a trill. Each of these words has a morpheme boundary coinciding with the syllable division before the rhotic consonant; the trills correspond to the word-initial trills found in raya 'line', Ciudad Real "Ciudad Real", and romántico "Romantic". The tap is found in words where there is no syllable boundary between the obstruent and the following rhotic consonant, such as sobre 'over', madre 'mother', ministro