Shouldn't "by the thousands" be "in the thousands"?

I have this question about "in the thousands" and "by the thousands" here:

On Friday night, crowds swelled by the thousands in downtown Hong Kong to listen to speeches from organizers, signaling the pro-democracy movement still has momentum after calls for a big rally.

Shouldn't "by the thousands" be "in the thousands"? Like, "people came in the thousands"?

If both "by the thousands" and "in the thousands" are valid English, how are they different?

• Why do you think "in the thousands" might be OK? Oct 13, 2014 at 2:58
• @user3169 Is "in the thousands" a corruption of "by the thousands"? I noticed that the article is written by three authors, two of which are likely non-native English speakers. Oct 13, 2014 at 3:09
• Sorry I don't follow you. I did not find "in the thousands" in the article. Oct 13, 2014 at 3:21
• @user3169 What I meant is that "by the thousands" is used in the article when "in the thousands" should be used. Oct 13, 2014 at 3:36
• @user3169 So, The "by" in "people came by the thousands" and the "by" in "Crowds swelled by the thousands" are different? Oct 13, 2014 at 4:53

In English one of the uses of "by" is to describe the quantities of batches. It has two general forms.

First, in the most literal way, we would say that you can buy eggs by the dozen (dozen == 12); eggs come in cartons of 12 eggs each, you cannot buy arbitrary numbers of eggs, you can only buy them in cartons, each of which has twelve. So at any given time, you can buy 12, 24, 36, etc. We express this idea by saying that they are sold by the dozen.

Second, that locution has come to be used to indicate scale. It is as if it implies, "these are the units you would find most convenient to count them in." If someone says of a terrible famine, "people died by the score" (score == 20), they do not mean that people literally died in groups of twenty, but that approximately several or many twenties of people died. As a native speaker, I would understand that to mean approximately 80 +/- 40. Or, for another example, "he smoked cigarettes by the pack" does not mean the smoker in question stuck twenty cigarettes in his mouth at once, but that he went through at least one, and possibly several, packs each day, or at least at a fast enough clip to recommend buying them more than one at a time. If someone says "within weeks, they were selling the new flavor of jam by the ton", it doesn't usually mean the jam was sold in one ton increments, but that the total amount of orders would most naturally be indicated in tons.

On Friday night, crowds swelled by the thousands in downtown Hong Kong to listen to speeches from organizers

is using the latter sense. It was not the case that batches of one thousand people were showing up together, but rather some unspecified quantity of people showed up, which was some amount best represented by an approximation of a smallish integer and three zeros.

• In "people died by the score", it is singular. But in "crowds swelled by the thousands", it is plural. Oct 13, 2014 at 17:23
• Yes. Did you have a question about that? Oct 13, 2014 at 21:50
• Could I write "crowds swelled by the thousand" instead of "crowds swelled by the thousands"? Oct 13, 2014 at 22:19
• Hmm! That sounds wrong to me; when you use a number, you use the plural, as in the above example "by twos and threes". But "dozen" is funny; note that it works like "by the pack" and "by the ton" which have to be singular. While "dozen" does mean "twelve", it perhaps is best thought of as "batch of twelve". Oct 13, 2014 at 22:26
• Does "the thousands" refer to a single unspecified number (with three trialing zeros), or a bunch of unspecified numbers (with three trialing zeros)? Oct 13, 2014 at 23:13

"People came in the thousands" means that thousands of people came. "People came by the thousands" means the same thing, and is equally valid English.

"Crowds swelled by the thousands" means that the size of the crowd increased by thousands of people. The word by is used to compare the size of the crowd before-versus-after the crowd "swelled".

"Crowds swelled in the thousands" is not correct English.

• So, "people came by the thousands" would be poor English? Oct 13, 2014 at 2:48
• I would only use "by the thousands" in these examples. Oct 13, 2014 at 3:03
• @meatie, "People came by twos and threes" means people arrived in groups of 2 or 3 at a time. "People came by the thousands" has the same meaning: people came in groups of thousands at a time. Oct 13, 2014 at 4:23
• @ThePhoton So, The "by" in "people came by the thousands" and the "by" in "Crowds swelled by the thousands" are different? Oct 13, 2014 at 4:53
• @meatie, I think the "crowds swelled" example is poorly written. They might mean it in the same way, "in groups of thousands at a time" or the author might have had some other meaning in mind. Oct 13, 2014 at 4:55

Crowds swelled by the thousands suggests that if you were counting the people coming in, you'd have to count them in groups of a thousand or more at a time to have an easy-to-count number of groups. This is a rather inexact measurement.

Crowds swelled in the thousands does not sound right, I'd guess it's non-standard English. Sometimes grew in the thousands is used, but means grew to the thousands, which is the same meaning as:

Crowds numbered in [or grew to] the thousands means that the total number of people in the crowd would be measured in the thousands. It does not suggest whether the crowd grew quickly or slowly.

To be more concise: by [unit]s suggests growth, in [unit]s suggests an end count.