Double consonants in English: Graphemic, morphological, prosodic and etymological determinants

,

This correlation of certain word endings with either single or double consonants is often discussed in terms of the words’ etymology: For Rollings (2004: 81f.), this behavior is an indicator of whether a word belongs to the ‘native’ or the ‘Latin’ part of the lexicon. The basic insight is that consonant doubling is rarer in words of Latin origin and more frequent in ‘native’ words, but that it is hard to model this behavior synchronically (cf. also Carney 1994: 116).

To test the effect of word endings on consonant doubling, three corpus analyses were carried out.

1. 
   The first analysis is a purely graphemic investigation: Which word endings occur with double consonants (e.g. as in ), which do not (e.g. as in ), and which occur with vowel letter clusters ( as in )?
   
2. 
   The second analysis takes the speller’s perspective and asks: How are short vowels marked, and how much is this spelling determined by the word ending?
   
3. 
   The third analysis takes the reader’s perspective and asks whether words with single intervocalic consonant letters (e.g.
   , ) correspond to words with a short or a long vowel phoneme (or a diphthong) in the first syllable.
   

These three analyses will be described in the following. They are all based on bisyllabic words: As Carney (1994: 123) states, apart from the Latin prefixes mentioned above, monomorphemic three or more syllable words hardly contain double consonants (cf. e.g. , , ).

4.1. Graphemic analysis

To determine the relation between word endings, single/double consonants and single vowels/vowel letter clusters, we use CELEX. More specifically, we use the set of all words in CELEX that meet the following requirements:

• 
  the word is not annotated as morphologically complex in CELEX (remaining morphologically complex formations on free bases are manually filtered)
  
• 
  the word is graphemically bisyllabic (), or trisyllabic with single final (
  )
  
• 
  the word contains a single or double consonant letter after the first vowel letter or vowel letter cluster
  

This leads to a sub-corpus of 2,324 words. On a purely graphemic basis, we determined for each word ending how many words contain a single vowel letter followed by a single consonant letter (, as in limit); or a single vowel letter followed by a double consonant (, as in hammer); or a cluster of vowel letters followed by a single consonant letter (, as in eager). The pattern , though logically possible, is very rare. It occurs only three times in the corpus (, ,
). Apparently, the constraint found for morphologically complex words extends to morphologically simple words: No consonant doubling after vowel letter clusters.

The following table summarizes the results. It indicates whether a pattern is systematically attested for a given word ending, and (if more than one pattern is attested) which pattern is dominant. ‘Systematically attested’ in this context means that at least 10% of the words with a given ending fall into the respective category (, , ). This is indicated by the symbol ‘’. Accordingly, for -er in table 1 below this means that all three patterns occur with more than 10% of the -er-words. Information about the respective dominant pattern is included in the next line: ‘80%’ means a dominant pattern occurs in more than 80% of the cases; ‘60%’ means it occurs in more than 60%, and ‘40%’ means the dominant pattern occurs in more than 40% of the cases. For the ending <-er>, for example, VCC is dominant with more than 60% of all words with <-er> falling in this category. Only word endings which occur 15 times or more are listed in the following table.

group	VC	VCC	VVC	word endings
1		 >60%		-er, -y
2	 >40%			-on
3	 >60%			-ish, -o, -ure, -or, -an
4		 >60%		-ing, -et
5		 >40%		-in
6	 >40%			-ot, -ar, -ey, -en, -age, -ard
7	 >60%			-ect, -a, -al, -is
8	 >80%			-ic, -i, -us, -um, -ile, -ate, -ent, -it
9	 >80%			-our, -id
10		 >80%		-ow, -ock

Table 1: Graphemic patterns (, , ) associated with different word endings. : systematically attested (> 10% of words with this ending occur with this pattern). >80%: Dominant pattern > 80%; >60%: dominant pattern > 60%; >40%: dominant pattern > 40%.

Ten word endings are correlated strongly (i.e. >80%) with one pattern: groups 8 and 9 (<ic>, <i>, <us>, <um>, <ile>, , <-ent>, <-our>, <-it>, <-id>) occur predominantly with patterns, and group 10 (<ow>, <-ock>) occurs predominantly with patterns. In other words, if a speller knows the word endings is one of these twelve, the dominant pattern already follows on a graphemic basis. For the great majority of word endings, however, there is graphemic variation – they occur with both single and double consonants.

4.2. The marking of short vowels in spelling

The second analysis takes phonology into account and investigates how short vowels are marked in spelling. Do words with a single intervocalic consonant phoneme and a short vowel in the first syllable correspond to words with consonant doubling (e.g. ) or with single intervocalic consonants (e.g. )? The data base to answer this question is the set of all words in CELEX that meet the following requirements:

• 
  the word is not annotated as morphologically complex in CELEX (remaining morphologically complex formations on free bases are manually filtered)
  
• 
  the word is phonologically bisyllabic; the first syllable is stressed
  
• 
  the word contains a single intervocalic consonant phoneme which corresponds to a consonant letter that can be doubled¹¹
  

This leads to a set of 1,583 words. Cross-classifying vowel quality (short vs. long/diphthong) over single vs. double consonants (/), we get:

			total
short	323	708	1,031
long + diphthong	549	3	552
total	872	711	1,583

Table 2: The relation between consonant doubling and phonological vowel quality. Data base: trochaic CELEX entries with one intervocalic consonant phoneme.

The majority of words with short vowel phonemes has a doubled consonant in their corresponding graphemic form (708 of 1,031, or 69%), as table 2 shows. Words with long or diphthong vowel phonemes almost never occur with doubled graphemic consonants (3 of 552, <1%). The three words which do occur are the ones mentioned in the last section, , , and

, which are all of French origin. So words with short vowels are often spelled with doubled consonants; long vowels or diphthongs almost never are. Having a short vowel is thus a necessary condition for consonant doubling.

Focusing on the 1,031 words with short vowels, we ask what determines the distribution in table 2. As noted by Carney (1994), Rollings (2004) and others, the ratio of doubled consonants varies depending on the word ending. The following table presents single vs. double consonants for word endings which occur at least ten times. 20 spellings with vowel letter clusters were excluded, e.g. treadle, zealot, meadow, flourish; in these cases, consonant doubling cannot be expected for graphotactic reasons (see above).

word ending			total	%	examples
ock		14	14	0%	hammock, haddock
le	2	127	129	2%	shuttle, pickle
er	3	93	96	3%	trigger, hammer
ow	2	34	36	6%	sorrow, mellow
y	12	109	121	10%	carry, city
ey	2	13	15	13%	valley, money
et	9	54	63	14%	socket, planet
a	3	16	19	16%	comma, para
ar	3	8	11	27%	collar, vicar
o	6	14	20	30%	ghetto, demo
in	6	14	20	30%	tiffin, robin
ot	4	6	10	40%	maggot, spigot
age	10	9	19	53%	image, scrimmage
on	13	11	25	54%	melon, gallon
ish	11	2	13	85%	finish, parish
ic	20	3	23	87%	critic, panic
it	14	2	16	88%	spirit, edit
id	16	2	18	89%	rapid, solid

Table 3:Marking of short vowels with single/double consonants according to word ending. All word endings that occur 10 times or more in the sub-corpus.

Taking 20%/80% as arbitrary thresholds, the word endings in table 3 fall into three groups, those with mostly doubled consonants (22.a), those with mostly single consonants (22.b) and those in between the two groups (22.c):

(22) a. >80% : <-ock>, <-le>, <-er>, <-ow>, <-y>, <-ey>, <-et>, <-a>
b. >80% : <-id>, <-it>, <-ic>, <-ish>
c. 20-80% : <-ar>, <-in>, <-ot>, <-age>, <-on>, <-o>

From the purely graphemic overview given above (table 1 above) it follows that the distribution of <id>, <-it>, and <-ic> on the one hand and of <-ock> and <-ow> on the other hand are hardly surprising: In all those cases, there are no graphemic alternatives, e.g. no graphemic words ending with double consonant followed by , or no graphemic words endings with single consonant followed by . The other word endings in (22) extend the list determined purely graphemically, and also the one from the pertinent literature (21 above). Moreover, what is striking about the word endings in (22) is that all endings that prefer single consonants involve the vowel letter . The letter , on the other hand, is found in many of the word endings that prefer double consonants. This is true for the whole corpus as well: Overall, 200 of 232 words with following a single or double consonant (e.g. , ,