Example of some words which always use as singular form?
he / she / Chinese / sheep / deer / fish / Swiss / species / crossroads / barracks / headquarters / offspring / data / dice / aircraft
The noun 'digs', a word for living quarters, a plural form used as a singular or plural, called an aggregate noun. Aggregate nouns are words representing an indefinite number of parts; aggregate nouns have no singular form. Example singular: Stop by my digs anytime. Example plural: The digs in the projects are plain not fancy.
Both are correct: The form boss's is the singular, possessive form of the singular noun boss. Example: You will need the boss's authorization for that expense. The form bosses is the plural form for the singular noun boss. Example: How many bosses do your have? Note: The plural possessive form is bosses'. Example: The bosses' meeting is at ten.