Take upon onself

quaerereverumShe took upon herself to improve her work.

She gave herself an assignment.
She "assumed" the task.
She took on the job of improving her work.

Thank you very much Avangi for explanation.

For some reason the sentence sounds better to me with an 'it': She took it upon herself....Anyone else?

Philip For some reason the sentence sounds better to me with an 'it': She took it upon herself....Anyone else?

I agree, it's more common.

Or we could say, "She took upon herself the job of improving her work." (no "it")

Or, "She undertook to improve her work." ("She undertook it to improve etc." would sound strange.)

Philip For some reason the sentence sounds better to me with an 'it': She took it upon herself....Anyone else?

Count me in. In fact, my first thought after reading the OP's sentence was "He left out the it".

The grammar of the verb "undertook" is different from the grammar of the idiom "take it upon oneself", but that's not really surprising.

CalifJimmy first thought after reading the OP's sentence was "He left out the it".

Do I hear a second?

Thank you very much folks for elaborate explanation.

My Google research gave me

took upon himself to 1.2 million
took it upon himself to 4.9 million

I guess both are used, but I am not at all familiar with that first, lesser used form, so it sounds wrong to me.

CJ

If you'd just agree to use it once out of every five times, I'd be happy.