In classifier languages without inflectional plurals neither counters nor measures ever take plural markers and, unlike typical noun class systems, the classifiers themselves practically never vary lexically for number.
Standardized
IF a classifier language has no inflectional plural, THEN neither counters nor measures take plural markers. IF a classifier language has no inflectional plural, THEN classifiers themselves never vary lexically for number
In Guami (Chibchan), I ‘person’ is used as a classifier with ‘one’ and NI ‘people’ with numbers greater than one (Alphonse 1956: 13); mentioned in Greenberg 1972.