When a verb has two or more subjects connected by and, it must agree with them in the plural. A similar rule applies to the agreement of the pronoun.
CORRECT THE FOLLOWING ERRORS.
+Model+.—Poverty and obscurity oppresses him who thinks that it is oppressive.
Wrong: the verb oppresses should be changed to oppress to agree with its two subjects, connected by and. The pronoun it should be changed to they to agree with its two antecedents, and the verb is should be changed to are to agree with they.
Industry, energy, and good sense is essential to success.
Time and tide waits for no man.
The tall sunflower and the little violet is turning its face to the sun.
The mule and the horse was harnessed together.
Every green leaf and every blade of grass seem grateful.
+Model+.—The preceding sentence is wrong. The verb seem is plural, and it should be singular; for, when several singular subjects are preceded by each, every_, or no, they are taken separately.
Each day and each hour bring their portion of duty.
Every book and every paper were found in their place.
When a verb has two or more singular subjects connected by or or nor, it must agree with them in the singular. A similar rule applies to the agreement of the pronoun.
CORRECT THE FOLLOWING ERRORS.
One or the other have made a mistake in their statement.
Neither the aster nor the dahlia are cultivated for their fragrance.
Either the president or his secretary were responsible.
Neither Ann, Jane, nor Sarah are at home.