two times or twice

  1. In the 1980’s the rate of increase of the minority population of the United States was nearly twice as fast as it was in the 1970’s.
  2. In the 1980’s the rate of increase of the minority population of the United States was nearly twice what it was in the 1970’s.
  3. In the 1980’s the rate of increase of the minority population of the United States was nearly two times faster than that of the 1970’s.
  4. In the 1980’s the rate of increase of the minority population of the United States was nearly two times greater than the 1970’s.

Can anyone explain correct grammatical sentence between these ?


Solution 1:

This is a lexical matter: 'rate' is a measure of speed, so in formal discourse it gets bigger or larger rather than faster - it's the increase which gets faster.

There are, however, less cumbersome ways of expressing this:

In the 1980s the minority population of the United States

  • grew twice as fast as it had in the 1970s. OR
  • grew two times faster than it had in the 1970s. OR
  • grew at twice (or two times or double) the rate it had (grown) in the 1970s.

Solution 2:

There is no difference in meaning between two times and twice, only a slight difference in usage.

If you have to pick between them, choose twice, because it is the special, dedicated word that means two times over. In all these examples, it sounds more natural to use twice, perhaps especially in the last pair:

  • My car is twice as fast as yours.
  • My car is two times faster than yours.

  • I ran twice as fast as you.
  • I ran two times faster than you.

  • I’ve already called them twice now.
  • I’ve already called them two times now.

Twice is just the word for two times. The word for just one time is once. The word for three times is thrice. There is no word for four times, as this question reveals.

That’s really all there is to it.