Question 1 (Consolidate)
The table below contains nouns which have irregular plurals. Complete the table (the first example has been done for you) by identifying the irregular plural, the type of irregular plural (you may need an etymological dictionary for this), and whether the noun can also take the regular plural inflection.
| Singular noun | Irregular plural | Type of plural | Can a regular plural be used? |
| cactus | cacti | regular Latin plural | yes – cactuses |
appendix | | | |
bacterium | | | |
criterion | | | |
datum | | | |
fish | | | |
goose | | | |
kibbutz | | | |
mouse | | | |
stigma | | | |
syllabus | | | |
Answer
| Singular noun | Irregular plural | Type of plural | Can regular plural be used? |
| cactus | cacti | Latin plural | yes – cactuses |
| appendix | appendices | Latin plural | yes – appendixes |
| bacterium | bacteria | Latin plural | no |
| criterion | criteria | Greek plural | no |
| datum | data | Latin plural | no/rarely – datums |
| fish | fish | zero inflection | yes, sometimes – fishes |
| goose | geese | vowel mutation | no |
| kibbutz | kibbutzim | modern Hebrew plural | yes – kibbutzes |
| mouse | mice | vowel mutation | yes, sometimes – mouses |
| stigma | stigmata | Greek plural | yes – stigmas |
| syllabus | syllabi | Latin plural | yes – syllabuses |
Question 2 (Explore)
Where there is the possibility of using the regular plural form or the irregular one, what factors are likely to influence the user’s choice?
Answer/discussion
In some instances, speakers may not know the irregular plural forms. If they do, they may avoid them in certain contexts, particularly informal speech, where it could sound pretentious to use the irregular plural. Sometimes, the irregular plurals have a more specialised use than their regular counterparts. For instance, stigmata is used in a religious context to refer to Jesus Christ’s crucifixion wounds. Newer meanings of words with irregular plurals tend to have a regular plural ending. For example, mice is used for the rodents, but mouses for computer hardware. Fishes is occasionally found, for example in the song ‘Three little fishes’ or the biblical story of ‘the loaves and the fishes’. Young children often use regular plurals (fishes, gooses, mouses) before they learn the irregular forms, and adults may adopt them in order to imitate children’s language, or for humorous effect.
Question 3 (Explore)
Are there any further issues relating to the irregular plural forms?
Answer/discussion
Three examples – bacterium, criterion and datum – require comment here. Bacterium tends to be found only in a technical, scientific context, so the plural bacteria is generally more commonly known and used. Because of this, some speakers may treat bacteria as a singular noun. The singular/plural distinction between Greek-derived criterion/criteria often causes confusion (as does phenomenon/phenomena), so again speakers may use the plural form as a singular. Data is so commonly used that it’s treated as both a plural form and as a singular non-count noun. However, datum is still used in specialised – particularly scientific – contexts, and may even occur as datums in the plural.
