Taking sides

If you were siding with one particular person, you would be "taking a side". But when people take opposite views, the act is called "taking sides". I believe it's to imply that there is more than one side, even though it is redundant. I think it has developed from slang, though. I believe the correct use is singular.

I don't think the point is in the object (i.e. the side), but rather the subject (i.e. that which takes a side). If one speaks to a singular subject, then it is "taking a side." However, when two or more subjects are present and being addressed, then it is considered "taking sides," though that, for one reason or another, presupposes that there must be at least one person on each - if only two - side.

Taken in context, I think 'taking sides' usually refers to the point at which opinions, beliefs, etc. become sufficiently discreet and different so that the 'sides' or 'opposing views' can be taken or iterated. So, we might hear 'They've just begun discussing, and not yet 'taken sides' as to whether the policy was right or wrong.

"Taking sides" is the common phrase, I suspect because that way you don't have to count up sides, or determine anyone's specific position. You can simply observe that they've gotten to the point of taking sides.

The British use of "side" for what Americans call "team" explains this, I believe. Taking sides is the point at which players in a casual game choose teams. To Americans this sounds more like an abstraction, but it's actually a very concrete metaphor.

I think Phil hit the nail on the head, while everyone else is missing the point.

It would be incorrect to say:

I'm taking sides with Kelly.

but correct to say

Everyone is taking sides except you, Fransbis.

Sorry, kortazone, "I'm taking sides with Kelly" is what most Americans would say--it's OK. However, "I'm siding with Kelly" eliminates the problem.

"I'm not ready to take sides on this." Also common, also correct.

The wages of sin is death.