In our last unit, we talked about assimilation, when speech segments become more similar to nearby sounds because of coarticulation. There are other articulatory processes that shape the words that we say. Some of these processes occur simply as a result of speaking quickly and naturally. Some of them make speech more clear for a listener. Some of them happen over time within a dialect, as speakers start unconsciously changing the way they produce sounds.
While we were learning to do IPA transcription we talked about vowel reduction. It’s a very common process in rapid, natural speech. In English, the vowel in an unstressed syllable often gets reduced to the mid-central vowel schwa [ə]. This happens in lots of words. For example, we don’t usually pronounce this word electric as [ilɛktɹɪk]. Instead, because the first syllable is unstressed, the vowel gets reduced, and we say [əlɛktɹɪk]. Likewise, this word today doesn’t get pronounced as [tudeɪ]. The vowel in the first, unstressed syllable gets reduced and we say [tədeɪ].
In fact, sometimes an unstressed vowel gets reduced so much that it disappears altogether! This process is called, obviously, deletion. In some varieties of English, reduced vowels are systematically deleted in certain predictable environments, like in police or garage. Deletion can also occur within consonant clusters. It’s pretty common for speakers to delete the first [ɹ] in surprise or the [d] in Wednesday. Deletion also happens when we borrow words from other languages. For example, take the Greek word pteron, which means “wing”. When we borrow this word and incorporate it into helicopter, we pronounce both the [p] and the [t]. But when it comes at the beginning of a borrowed word, like pterodactyl, we just delete the [p] altogether, since English doesn’t allow two stops in a syllable onset.
Sometimes when we’re speaking, extra segments find their way into our words, as a result of coarticulation. Can you guess what word I’m saying? [phɹɪnts] Was it prince or prints? Only one of them is spelled with a “t”, but we pronounce them both the same way. In prince, an alveolar stop appears between the alveolar nasal and the alveolar fricative. The articulatory process that inserts an extra sound is called epenthesis. In English, this tends to happen between nasals and stops or between nasals and fricatives. Another example is in the word something, where we often epenthesize a little bilabial stop [p] between the bilabial nasal [m] and the voiceless fricative [θ]. Or when George W. Bush famously pronounced the word nuclear as [nukjəlɚ], he was epenthesizing a [j] between the [k] and [l].
Some articulatory processes result from speech errors. Some of these errors are characteristic of children’s speech, and some of them just occur in everyday rapid speech. Children’s speech often includes the process of metathesis, exchanging the position of speech segments. When my niece was little, she used to pronounce the word hospital as [hɑstɪbəl], exchanging the positions of the two stops. Metathesis can also happen when we borrow words from another language. When English speakers want to buy a burrito from the restaurant chain called Chipotle, we often metathesize the [t] and [l] and say, [tʃəpolti], because the “tl” sequence is rare in English.