English has borrowed a great many words from ancient Latin and Greek. The general trend with those borrowed words is toward what is called Anglicization or naturalization, in other words reformation of the word and its inflections as normal English words. As we have already mentioned, the plural of ‘English’ English words is formed by adding an -s at the end of the word etc. However, certain English nouns, especially of a Latin origin, have kept their original Latin plural form and that is where we might have some problems. In some cases, both forms are still competing. The choice of a form can often depend on the context: for a librarian for example, the plural of appendix is appendices; for a physician the plural of the same noun is appendixes.
Let’s recall some nouns that are always used in plural but take a singular verb
| Endings | Singular form | Plural form |
|———|—————|————-|
| -a | -ae | algae / -i/ |
| -is | -es | analyses / -seez/ |
| -ix | -ices | matrices or matrixes |
| -on | -a | criterion |
| -um | -a | bacterium |
| -us | -i | radius |
| -ies | -ies | species |
Let’s recall some most common nouns of Latin & Greek origin and their plurals
| Noun (Latin) | Plural |
|————-|——–|
| datum | data |
Since data is plural it would be logical to use it with a plural verb (These are important data). However, today it is commonly used as an equivalent to information, followed by a singular verb (This is interesting data.)
