BY vs IN

I can suggest about the first it must be "he made a big mistake by doing that"

By usually means before a due date, "Finish by Friday," or it names the doer of an action as it does here.

If you say "He wasted no time by kissing her," you would be saying he avoided waisting time by kissing her (he was the doer of the action). Your understanding of in is correct and it would be the more common thing to say.

So for number 2 its IN but what about number ONE?

Does number 2 MEAN WHAT I think it means?

thanks

1) In 1 they are so close to the same thing that I can not draw a clear difference. "by" would be more common useage.

2)Yes.

I have these thoughts:

jemaasjr
By usually means before a due date, "Finish by Friday," This I buy. or it names the doer of an action as it does here. I have to ponder on this one...

If you say "He wasted no time by kissing her," you would be saying he avoided waisting time by kissing her (he was the doer of the action). Your understanding of in

Well, reading your comments, my own, and looking it up in a dictionary, there seem to be two major uses for by.

1)The first and most frequent use is that it specifies the means or manner in which something is accomplished. When you say the house was built by the men, you are not so much specifying the builder as specifying the means. A man liv

In a nutshell, I think we are on the same page.

X by Y = X intersects Y. I agree it's not a direction.

I've reserved a table by the window. By = next to.

So the point is, in order to define whether the use of "by" is correct, it really depends on the entire context.

Prepositions are difficult for native speakers, too. Yes, "in" or "by" are probably (probably) both correct for "He made A big mistake __ doing that." BUT if you say "He made THE big mistake," then you must finish with "OF doing that." English is, indeed, a difficult language!!!