It's "earnings are" (not "earnings is"). "Earnings" is a plural noun, and therefore takes a verb in the plural.
It's "earnings are" (not "earnings is"). "Earnings" is a plural noun, and therefore takes a verb in the plural.
The company's annual earnings are increasing substantially.
The company's annual earnings is increasing substantially.
Follow the same convention with other verbs; thus, we say "earnings have" (not "earnings has").
The company's earnings have increased by different amounts in the past several years.
The company's earnings has increased by different amounts in the past several years.
Remember, plural nouns, like "earnings", take a plural pronoun.
Robert declared his earnings to the tax authorities. They have increased at a slower pace.
A partial list of other related plural nouns that also take a plural verb:
