There are four named arguments that control the pluralization:
|no_comma= By default, commas (or semi-colons) will cause the text string to be considered plural. Setting |no_comma=1 turns this behavior off.
|any_comma= By default, commas (or semi-colons) that are adjacent to digits are singular. Setting |any_comma=1 turns this behavior off.
|no_and= By default, "and" causes a string to be plural. Setting |no_and=1 turns this behavior off.
|parse_links= By default, wikilinks are considered to be unparseable (singular) objects. Setting |parse_links=1 will allow the parser to read the contents of the wikilinks and determine whether that makes the string plural.