1.21 same form for singular and plural

Some count nouns have the same form for both singular and plural.

• ...a sheep.
• ...nine sheep.

Many of these nouns refer to animals or fish, others are more varied in meaning:

bison, deer, greenfly, grouse, moose, reindeer, sheep, --- , cod, fish, goldfish, halibut, mullet, salmon, shellfish, trout, whitebait, --- , aircraft, hovercraft, spacecraft, --- , crossroads, dice, fruit, gallows, grapefruit, insignia, mews, offspring, series, species, --- , bourgeois, chassis, corps, patois, précis, rendezvous