the s-genitive

English has two genitive forms: of and the s-genitive (singular 's and plural s'). Although the s-genitive should only be used with human (or animals), you will increasingly notice it being used, especially in newspapers and magazines, to refer to inanimate objects. However, when writing more formal texts at school or work, replace the s-genitive with one of the following three strategies.

The of-genitive

Poor: The momentum of a material object is defined as p = mv, the product of the object's mass and its velocity vector.   Better: The momentum of a material object is defined as p = mv, the product of the mass and velocity vector of the object.

One important use the "of" genitive form is in "that of" for reducing redundancy in comparisons.

Poor: This implies that there is additional memory other than the stored object's.   Better: This implies that there is additional memory other than THAT OF the stored object.

Noun compounds

For more information on this important form, see noun compounds.

Poor: A computer’s keyboard is an input device partially modelled after the typewriter.   Better: A computer keyboard is an input device partially modelled after the typewriter.