Stress Shift: Why 'Admirable' And 'Preferable' Change Stress?

Have you ever noticed how the stress in some words seems to shift when you add a suffix? It's a fascinating phenomenon in English pronunciation, and today we're going to dive deep into why words like 'admirable' and 'preferable' have the stress on a different syllable than their root words, 'admire' and 'prefer'. Guys, this is going to be a fun exploration of phonetics and word formation!

Unpacking the Stress Shift

So, what's the deal? Why do we say /ədˈmaɪər/ for 'admire' but /ˈædmərəbl/ for 'admirable'? And why is 'prefer' /prɪˈfər/ while 'preferable' is /ˈprɛfrəbl/? It all boils down to a complex interplay of factors, including the syllable structure of the words, the nature of the suffixes being added, and some good old-fashioned historical quirks of the English language. It's not just random, though; there are patterns and principles at play that can help us understand these shifts. Let's break it down step by step.

First, consider the base words: 'admire' and 'prefer'. In both cases, the stress falls on the second syllable. This is pretty common in two-syllable verbs in English. Now, when we add the suffix '-able' to create 'admirable' and 'preferable', something interesting happens. The '-able' suffix is what we call a stress-shifting suffix. This means its presence can influence where the primary stress falls in the derived word. But why does it shift the stress to the first syllable in these cases? To understand this, we need to delve into some linguistic principles.

One key factor is the concept of syllable weight. In phonology, syllables are considered to have different weights based on their composition. A syllable with a long vowel or a diphthong, or one that ends in a consonant, is considered a heavy syllable. Syllables with short vowels and no coda (a consonant at the end) are considered light syllables. English tends to prefer stress on heavy syllables. When we add '-able', the first syllable in both 'admirable' and 'preferable' becomes relatively heavier compared to the second syllable. In 'admirable', the first syllable /ˈæd/ is closed by a consonant, making it heavier. In 'preferable', the first syllable /ˈprɛf/ also ends in a consonant, contributing to its weight. The addition of '-able' doesn't just add a syllable; it changes the weight distribution within the word, nudging the stress towards the heavier syllable.

Another contributing factor is the rhythmic structure of English words. English has a tendency to alternate between stressed and unstressed syllables, creating a rhythmic pattern. This is known as the iambic-trochaic law. When we add '-able', stressing the second syllable would create a pattern of two unstressed syllables in a row (e.g., ad-mir-a-ble). This is less common in English than alternating stress patterns. Shifting the stress to the first syllable creates a more balanced trochaic pattern (stressed-unstressed-unstressed), which is more in line with the rhythmic preferences of the language. So, in essence, the stress shift helps maintain a more natural and rhythmically pleasing flow of pronunciation.

The Curious Case of '-able' Suffix

The '-able' suffix itself plays a crucial role in this phenomenon. It's a suffix that not only adds the meaning of