Rules and Tips to Solve Spotting Errors in Sentences 2

Rules and Tips to Solve Spotting Errors in Sentences:

4.There are some nouns that indicate length, measure, money, weight or number. when they are preceded by a numeral, they remain unchanged in form.

Foot, meter, pair, score, dozen, head, year, hundred, thousand, million.

a) It is a three years degree course.(Incorrect)
It is a three year degree course.(Correct)

5.Some nouns have one meaning in the singular and another in the plural.

authority = command ,authorities = persons in power, good = wise , goods = property, force = strength forces = army
content = satisfaction contents = things contained, physic = medicine physics = physical sciences, iron = metal, irons= fetter, chains.

Examples :
a) Air is necessary for human life.
b) It is bad to put on airs.