to practice in/at doing something

If I talk about an activity do I say ' while she practiced in/at doing that job'?

Quote:

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Originally Posted by allthewayanime

If I talk about an activity do I say ' while she practiced in/at doing that job'?

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What exactly are you trying to say?

This is the whole sentence: Aethelflaed wasn't new to this: in fact she had already practiced at/in doing her husband job as the ruler of Mercia before his death.

Quote:

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Originally Posted by allthewayanime

This is the whole sentence: Aethelflaed wasn't new to this: in fact she had already practiced at/in doing her husband job as the ruler of Mercia before his death.

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Where did you find it?

I made it from my history book and I would like to know if I should add a preposition: at or in?

Quote:

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Originally Posted by allthewayanime

I made it from my history book and I would like to know if I should add a preposition: at or in?

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No preposition is required. It's "practised" in BrE by the way.