I have a little confusion on understanding the sentence:
It took me all of ten minutes to find out .
Why couldn't it be "I took all of ten minutes to find out"?
I have a little confusion on understanding the sentence:
It took me all of ten minutes to find out .
Why couldn't it be "I took all of ten minutes to find out"?
The simple answer is you can use both. The phrasing is flexible.
"It took me ten minutes."
means the same as
"I took ten minutes."
The first phrase is probably more common and sounds more natural to an English speaker, but there is nothing more correct about it.
Actions consume resources. Took here is used to mean consumed:
Filling the hole took 12 bags of soil.
Driving to work took half a tank of fuel.
Beating the last level of the game took five attempts.
Finding out took ten minutes.
Sometimes it makes sense to specify who consumed those resources:
Filling the hole took Ted 12 bags of soil.
Driving to work took Alice half a tank of fuel.
Beating the last level of the game took you five attempts.
Finding out took me ten minutes.
Since "Filling the hole", "Driving to work" etc. are noun phrases, we can replace them with the pronoun it.
It took Ted 12 bags of soil.
It took Alice half a tank of fuel.
It took you five attempts.
It took me ten minutes.
But now that we've lost that detail, we may want to put it back in:
It took Ted 12 bags of soil to fill the hole.
It took Alice half a tank of fuel to drive to work.
It took you five attempts to beat the last level of the game.
It took me ten minutes to find out.
In speech, you might have already spoken "It took me ten minutes ..." before realising that you need to explain what "it" is, so you add it on afterwards. That's one reason a "backwards" form of the sentence exists.
Another reason is that it it allows you to emphasise one part over the other. The "taking ten minutes" part is the focus of the sentence, and what gets the listener's attention.
Written English mimics spoken English.
There is a subtle semantic difference between these two:
David took 10 minutes to find the notebook.
It took David 10 minutes to find the notebook.
In the first, David takes 10 minutes from his "supply of time", in order to find the notebook. David is giving his time to the activity.
In the second, the activity of finding the notebook, takes 10 minutes from "David's supply of time". The activity is taking time from David.
Although it's not the question, for completeness: "all of ten minutes" is a stock phrase meaning "ten minutes, which I consider to be a very small effort; you could have done the same".
The simple version would be "It took me ten minutes to find out"
“It took me all of ten minutes to find out” is to suggest that it took only a small amount of time. "All of" 10mins is a sarcastic way of saying that 10mins wasn't that much.
So we could say here, "it took me all of 10seconds to Google that answer"
Sentences generally require a subject, the person or thing the sentence is about, and in your second sentence the subject is I, that is, the person speaking. Because the grammar of a sentence needs a subject, we sometimes have to invent one, even though it has no meaning. That is the case in your second sentence. It is there simply to meet the grammatical requirement, and because it is empty of meaning it is called a‘dummy it’. (But now see comments below.)
Both of them are meaningful and grammatically correct. They are also similar in meaning. The only difference between them is their sentence constructions. The first sentence takes the form of "It + (conjugated form of take, e.g., took) + object + time taken (length/amount of time) + to-infinitive" whereas the second takes the form of "Subject + (take) + length/amount of time + to-infinitive", which is very simple in English grammar. Note that the subject it in the second form is known as dummy pronoun or empty subject or sometimes as impersonal subject.