Full Vowels–Reduced Vowels

Although stress is the topic we will discuss later, there is one issue that we will take up here, and this relates to reduced vowels. While all vowels of English (except [ə]) can occur in stressed syllables, many of these vowels reveal alternations with an [ə] in unstressed syllables in a morphologically related word.

We should immediately point out, however, that a vowel’s appearance in an unstressed syllable does not necessarily result in a reduced vowel [ə]. It is perfectly possible for the English vowels to appear in full (unreduced) form in unstressed syllables (or in syllables with secondary stress), as shown in the following:

Thus, the unidirectional generalization to be made is the following: while a reduced vowel is necessarily in an unstressed syllable, a vowel in an unstressed syllable is not necessarily reduced.

Although we have consistently used [ə] in reduced syllables, it is not uncommon to find an [ɪ] in people’s speech. That is, for a word such as implication we can get [ɪmplɪkeʃən] as well as [ɪmpləkeʃən]. In general, [ɪ] is found before palato-alveolars (e.g. selfish [sεlfɪʃ], sandwich [sændwɪtʃ], marriage [mæɹ̣ɪʤ]) and velars (e.g. metric [mεtɹ̣ɪk], running [ɹ̣ Λ n ɪ ŋ]). It should be noted, however, that the syllable structure is also a factor. The influence of palate-alveolar/velar consonants is more visible when there is tautosyllabicity. For example, we tend to find [ɪ] in topic [tɑpɪk], which is likely to change to an [ə] in a related word such as topical [tɑpəkəl], because the velar, [k], is the onset of the following syllable. Individuals should check their pronunciation of such syllables and transcribe the vowels accordingly. However, since reduced syllables are necessarily unstressed, and [ə] cannot appear in a stressed syllable (but [ɪ] can), we encourage our students to use [ə] for such vowels, for practical reasons.

We should also point out that [ə], besides having this relationship with the unstressed [ɪ], has a special relationship with three other vowels, /i, o, u/. In unstressed syllables, the range of pronunciation values of these three vowels extends to the central [ə] area, as shown in the following: