Both editors in chief asked for leave of absences at the same time.

would the correct form be.... leaves?

Well, if both editors in chief are taking leave of absences at the same time, you could say that they are "leaving" or "taking leave." But if you want to use the plural form of "leave," then yes, it would be "leaves." Just imagine a bunch of leave-taking editors in chief scattering around. How chaotic would that be, huh?

No, the correct form in this sentence would be "leave" without the 's'. The word "leave" functions as a noun in this context, referring to the requested period of absence. So, the sentence should be written as: "Both editors in chief asked for leave of absences at the same time."

To determine whether the correct form is "leaves" or something else, we need to understand the subject-verb agreement in this sentence.

Here's the breakdown of the sentence:
Subject: Both editors in chief
Verb phrase: asked for leave of absences

In this case, "Both editors in chief" is treated as a plural subject because of the word "both." When a plural subject is used, the correct form of the verb typically does not take an "s" at the end.

Therefore, the correct form in this sentence would be "asked for leave of absences."

Yes.

Both editors in chief asked for leaves of absence at the same time.

http://grammar.ccc.commnet.edu/grammar/compounds.htm#plurals