"It's all about the focus of the investigation," she said. "At the beginning, this was a search. It's still a search, but the focus now of the search is as a criminal investigation."  (quoted from cnn.com)

Should it be "At the beginning" or "In the beginning"?  

Thanks for the examples and explanation, Clive. I have learned that "in the end" means "finally", and "at the end"  is used to indicate 'at the end' of something;where 'something' is a noun. Therefore, in the same way, I derived the meanings of 'in the beginning' and 'at the beginning' in such a way that "In the beginning" means 'initially' and "At the beginning" means at the 'at the beginning' of something;where something is a noun.

With the above understanding, I was thinking "In the beginning" woule be more suitable in the example sentence;however, now I understand the difference between them is subtle. Does my understanding match with your thoughts and explanations on this topic?, or Am I totally out of track?

Clive wrote:

Hi Krish, Well, the difference is so little, and so subtle sometimes, that I really think a lot depends on the sentence and context. And even then, they may sometimes be interchanged. If you like, post a few sample sentences to illustrate where you may feel unsure. Clive

Hi Clive,

Thanks. I will post few sentences tomorrow.

Hi Krish,

My questions as follows. I am curious to learn the the contexts in which the use of "in/at the beginning/end" would be wrong. I have framed some sentences, using my understanding on this topic. Could you please review them  and explain to me if "at" can be replaced by "in" in any of these sentences?

(1) I found a hundred-dollar bill at the end/at the beginning of Washington street.  Not 'in'. I think a street is more commonly considered to have two 'ends'. It seems a little unusual to speak of its 'beginning'. Google confiems this.

(2) In the beginning ,I thought the caller was a female. This suggests I spent some time with this understanding. 'At' is OK, but suggests I found out the truth immediately.

(3) At the beginning of the tele-conference, I thought the caller was a female. Same comment as 2 above.

(4) My home is at the end of Washington street. OK. Not 'in'.

(5) I was waiting for my friend at a movie theater for an hour ,and he didn't show up at all. In the end, I left the theater with frustration. OK. 'In' suggests I took a period of time to arrive at the decision to leave. 'At' sounds a bit odd. Probably because there is not 'the end of anything significant', just a period of waiting.

Best wishes, Clive

Hi,

Yes. The Bible says even God took a bit of time to create the world in the beginning.

Clive