What the difference between expansion and extension

English as a Second Language English Vocabulary, Grammar and Idioms
1

Hi there.

What the difference between expansion and extension?

I have checked it in a dictionary, and they both have similar meaning

2

They can have the same meaning in some contexts; but in others, there is a difference. There are also many specific collocations, in which one or the other is always used with a given word, even though there would be no real difference in meaning if they had been swapped.

In a very general description, one might define these verbs as follows:

  • To extend = to increase or be increased in length or distance, in one dimension;
  • To expand = to increase or be increased in size, in two or more dimensions.

In addition, to extend can mean: to move by a certain distance, or to have a certain length, in one dimension.

Both words are often used metaphorically, where this difference in dimension is more difficult to recognize, if it can be recognized at all.

Examples:

  • The bridge extends from one side of the gorge to the other. (one dimension: distance/length.)

  • France expanded rapidly during the reign of Louis XIV. (2: area)

  • Most gases expand when pressure is decreased. (3: volume)

  • The extension of the church was more expensive than our budget allowed. (?)

  • I can’t reach the socket: do you have an extension cable? (1: distance/length)

  • Peter extended a long branch to help John climb out of the water. (1: distance)

  • The volume of trade expanded tremendously. (3: volume [metaphor])

  • We did not know what to think, since she did not expand upon her remark. (?)

  • The word “do” can be extended by adding a suffix: the addition of “-ing” gives “doing”. (1: length)

3

Thanks