What does 줬는데요 mean?

What's the root word for 줬는데요?

For example in this sentence from the vlive video

유니콘 인형도 있어요. 제가 이름도 붙여줬는데요.
I have a unicorn doll. I gave a name to it.

이름도 붙여줬는데요 here means "naming" / "name giving"

Another example from Strong Woman:

지난 밤 4번째 납치 사건이 발생하면서 또 한번 충격을 줬는데요
Last night a fourth kidnapping incident occurred which has caused us great shock once again.

Here 충격을 줬는데요 means "gave a shock"

And when I search on Naver dictionary, it shows which has the root word as 주다 "to give" http://endic.naver.com/search.nhn?sLn=en&searchOption=all&query=%EC%A4%AC%EB%8A%94%EB%8D%B0%EC%9A%94

Most probably, 줬 comes from 주 but what does the rest of the suffixes mean in 줬는데요?

Why did the ㅜ become ㅟ and added the pachim ㅆ? Is that a common "mutation"?

What does 줬는데요 mean?

What's the root word for 줬는데요?

For example in this sentence from the vlive video

유니콘 인형도 있어요. 제가 이름도 붙여줬는데요.
I have a unicorn doll. I gave a name to it.

이름도 붙여줬는데요 here means "naming" / "name giving"

Another example from Strong Woman:

지난 밤 4번째 납치 사건이 발생하면서 또 한번 충격을 줬는데요
Last night a fourth kidnapping incident occurred which has caused us great shock once again.

Here 충격을 줬는데요 means "gave a shock"

And when I search on Naver dictionary, it shows which has the root word as 주다 "to give" http://endic.naver.com/search.nhn?sLn=en&searchOption=all&query=%EC%A4%AC%EB%8A%94%EB%8D%B0%EC%9A%94

Most probably, 줬 comes from 주 but what does the rest of the suffixes mean in 줬는데요?

Why did the ㅜ become ㅟ ㅝ and added the pachim ㅆ? Is that a common "mutation"?