MORE THAN vs LONGER THAN
It seems than often, when referring to time, MORE THAN and LONGER THAN are interchangable. Please correct me if I'm wrong.
eg. The boy studied MORE THAN five hours.
The boy studies LONGER THAN five hours.
However, sometimes this doesn't seem to be the case.
eg. Dinosaurs lived MORE THAN a million years ago. (This seems fine to me)
Dinosaurs lived LONGER THAN a million years ago. (This seems incorrect)
Why is this? Is it to do with the length of the time? Or is it just me? Is there nothing wrong?
Please help me out. Thank you.
In most uses, more refers to quantity, while longer refers to time or size. You can have more sand in a box, but a longer waiting time or a longer extension cord.
In the first example you gave, you can say it either way.
In the second example, you can use "longer than" if you just mean a length of time. However, you are meaning it as "when" rather than "how long." The concept of "when" is not a quantity, but a specific time, a time period, or in a broader sense, a location. You could say:
"Sometimes this brand of paint lasts longer than 5 years."
You could use it in reference to age, but it may be simpler in some cases just to use the word "older" for that.
"Some people live for longer than 90 years."
"Some humans live for over 90 years."
"Some humans live to be older than 90 years."
"Some people live past age 90." (I kept switching the subject for variety, not for grammar.)
Also, with the dinosaur sentence, "over" would work quite well.
"Dinosaurs lived over a million years ago."
|link comment||edited May 25 '12 at 15:19 Courtney Contributor|
I think the key is the word "ago." When using this preposition, the words "longer than" are not used. Notice that in the first case, we are talking about how long the boy studied, but in the second case we are talking about when the dinosaurs lived. So in the first case "longer than" and "more than" modify "studied" but in the second case, they tell us how long "ago."
I can't think of a real grammatical reason for this; I think it is just convention.
We could also use "over" in the same way as "more than"; it works in both cases.
|link comment||answered May 25 '12 at 15:46 sanjay Expert|
Sanjay spotted the reason. It is the preposition "ago". A similar pattern occurs with "of age".
I can't put my finger on the rule, but "more than" can be followed by prepositions like "ago" and "of age", while "longer than" and "over" cannot.
|link comment||answered May 25 '12 at 19:18 Jeff Pribyl Grammarly Fellow|
@ Jeff - "ago" is an adverb, not a preposition.
Much of this depends on the stylebook you are using. In journalism, it is absolutely WRONG to say, for instance, "Some humans live over 90 years." It would have to be MORE THAN, because you are referring to a numerical quantity. Colloquially, "over 90 years" is acceptable. I still wouldn't use it myself.
The "longer than" phrase feels awkward to me in all of the above cited cases but I can't give you a reason.
|link||answered May 26 '12 at 00:37 glorrierose New member|