# English Vowels II: Diphthongs and Reduction

Languages I · English Phonetics and Phonology · https://tryals.app/learn/languages-i/english-vowels-ii-diphthongs-and-reduction

## Vowels That Change During Themselves

A **monophthong** holds one quality throughout. In contrast, a **diphthong** glides from one vowel position towards another within a single syllable.

RP is conventionally analysed with **eight** diphthongs, divided into two groups:

| Group | Count | Movement | Examples |
|---|---|---|---|
| **Closing** | 5 | Towards a close vowel | *face*, *price*, *choice*, *goat*, *mouth* |
| **Centring** | 3 | Towards schwa | *near*, *square*, *cure* |

Centring diphthongs arose in **non-rhotic** accents when historical /r/ was lost. Rhotic accents such as General American never developed them.

### Schwa and Reduction

**Schwa** is the mid-central vowel heard in *about* and *sofa*. It is defined by three key facts:

- It is the **most frequent vowel in connected speech**.
- It occurs **only in unstressed syllables**.
- It is what full vowels **become** when stress is lost.

### Weak Forms and Rhythm

**Weak forms** apply reduction to function words such as *to* and *can*. Connected English speech uses these reduced forms by default.

English is traditionally called **stress-timed**, meaning stresses recur at roughly equal intervals. This contrasts with **syllable-timed** languages, where each syllable takes equal time.

Phonetic measurements show this distinction is actually a **gradient** continuum rather than a strict dichotomy. English rhythm relies on heavy vowel reduction rather than perfectly equal timing.

> **Common pitfall:** treating reduction as sloppiness. In English, reduction is systematic and helps listeners identify the stress pattern.

## Practice questions

8 of this lesson's 13 practice questions, with answers. The full set is in the app.

### 1. Schwa occurs only in unstressed syllables in English.

**Answer:** True

**Why:** **True**, and the restriction is absolute enough to be a diagnostic: if you can stress a syllable and keep the vowel, it was not schwa. Stressing the first syllable of *about* produces a different vowel entirely, which is why schwa and stress are two views of the same system.

Page: https://tryals.app/practice/languages-i/english-vowels-ii-diphthongs-and-reduction/schwa-occurs-only-in-unstressed-syllables-in-english

### 2. How many diphthongs does the standard analysis of RP recognise?

**Answer:** 8

**Why:** **Eight**: five closing and three centring. The centring set is the unstable part of the inventory. GA lacks it entirely, and within RP the *cure* diphthong is merging with the vowel of *thought* for many younger speakers.

Page: https://tryals.app/practice/languages-i/english-vowels-ii-diphthongs-and-reduction/how-many-diphthongs-does-the-standard-analysis-of-rp-recognise

### 3. Why does a speaker who uses only full forms become harder to follow, not easier? Select every true statement about weak forms.

A. Weak forms are a feature of careless speech and are avoided in formal registers
B. Connected speech uses the reduced form by default
C. Using only full forms produces a rhythm listeners do not expect
D. Function words have a full citation form and a reduced form with schwa

**Answer:** B. Connected speech uses the reduced form by default; C. Using only full forms produces a rhythm listeners do not expect; D. Function words have a full citation form and a reduced form with schwa

**Why:** The fourth is the persistent myth. Weak forms occur throughout formal speech, including in read news bulletins; what changes with register is speed and precision, not the existence of reduction. A learner drilled to avoid them ends up harder to follow, not clearer.

Page: https://tryals.app/practice/languages-i/english-vowels-ii-diphthongs-and-reduction/why-does-a-speaker-who-uses-only-full-forms-become-harder-to-follow

### 4. Sort each item by whether it is a CLOSING diphthong, a CENTRING diphthong, or a MONOPHTHONG.

**Answer:**

- Closing diphthong: The vowel of price, The vowel of goat
- Centring diphthong: The vowel of near, The vowel of square
- Monophthong: The vowel of see, Schwa

**Why:** The sorting is by direction of movement, and the centring group is the historically interesting one, every member of it corresponds to a word that once had a pronounced r, which is why the group exists in some accents and not others.

Page: https://tryals.app/practice/languages-i/english-vowels-ii-diphthongs-and-reduction/sort-each-item-by-whether-it-is-a-closing-diphthong-a-centring

### 5. Vowel reduction is frequently mischaracterised as phonetic sloppiness, yet phonologically it is a systematic rule of connected speech. What follows from this distinction for the listener's perception of spoken English?

A. It restricts vowel changes solely to monosyllabic function words
B. It forces listeners to restore lost phonemes via context clues
C. It creates equal temporal intervals between all syllable peaks
D. It provides contrast that marks the language's stress pattern

**Answer:** D. It provides contrast that marks the language's stress pattern

**Why:** Reduction is not an acoustic defect requiring contextual repair, nor is it confined to function words; unstressed syllables in content words reduce systematically. Crucially, acoustic timing in natural speech is gradient rather than strictly metronomic, making vowel quality contrasts vital for metrical parsing.

Page: https://tryals.app/practice/languages-i/english-vowels-ii-diphthongs-and-reduction/vowel-reduction-is-frequently-mischaracterised-as-phonetic

### 6. Complete the account of reduction.

**Answer:** A vowel whose quality glides within one syllable is a **diphthong**. The mid-central vowel that occurs only in unstressed syllables is **schwa**. Function words with a reduced pronunciation are said to have **weak** forms. English is traditionally called **stress**-timed, though the strong version is not supported by measurement.

**Why:** The last blank should be learned with its caveat attached. Rhythm metrics place languages on a continuum rather than in two boxes, and what is really different about English is the heavy reduction of unstressed vowels, not any equality of intervals.

Page: https://tryals.app/practice/languages-i/english-vowels-ii-diphthongs-and-reduction/complete-the-account-of-reduction

### 7. The centring diphthongs of RP are stable and show no signs of change.

**Answer:** False

**Why:** **False.** The *cure* diphthong is receding for many younger RP speakers, merging with the vowel of *thought*, and the *square* diphthong is monophthongising for many as well. The centring set is the least stable part of the inventory, which fits its origin as a by-product of r-loss.

Page: https://tryals.app/practice/languages-i/english-vowels-ii-diphthongs-and-reduction/the-centring-diphthongs-of-rp-are-stable-and-show-no-signs-of-change

### 8. Arrange the stages by which a full vowel becomes schwa in a derived word.

**Answer:**

1. The base word carries stress on a particular syllable
2. A suffix is added that shifts the stress elsewhere
3. The formerly stressed syllable loses its stress
4. Its vowel reduces towards the centre of the vowel space
5. The syllable is now pronounced with schwa

**Why:** The direction of causation is the point: stress moves first and reduction follows. That is why *photograph* and *photography* differ in the vowel of the second syllable although the spelling is identical, and why the spelling is no guide at all to the vowel in an unstressed syllable.

Page: https://tryals.app/practice/languages-i/english-vowels-ii-diphthongs-and-reduction/arrange-the-stages-by-which-a-full-vowel-becomes-schwa-in-a-derived