English nouns in plural form usually preserve the plural perception in Czech. However, terms that were imported in singular are rarely pluralized according to English grammar when the surrounding text requires plural. If a Czech plural ending cannot or is not added, the singular form is used as plural. Therefore, and for the sake of simplicity, all English nouns should be annotated with unknown number (X), unless they have a Czech ending.

English (and most other non-Slavic) nouns have unknown (X) case in citations but they can be sometimes declined in word use.