When someone has done some task that you have requested and they have done it particularly quickly then this is the correct way to say thanks:

早急なご対応ありがとうございます。

さっきゅうな　たいおう　ありがとうございます。

sakkyuna taiou arigatougozaimasu.

“Thank you for dealing with the matter so quickly.”

対応

たいおう

“taiou” is used a lot in my office - whenever someone “does” something its called “対応”.

I think this means “taking care of” or “handling” a task.

早急な

さっきゅう

sakkyu

This means “very quickly” - both kanjis mean “fast” as far as I can tell. The second one “急” is used for the “急行” きゅうこう ( express ) trains.

This one has got me many times..

影響範囲

えいきょうはんい

eiqyou hani

( spoken as “eiqyou hai - in” )

It literally means “the range of effect” and is used a lot when we are going to make a fix to a program or do some other engineering task, everyone wants to know what parts of the service the fix or the work will effect - ( 影響　えいきょう ) and what the scope of that effect will be - its 範囲　はんい )

I heat this all the time and tried to look it up but couldn’t find it anywhere. The reason is they say the second word like “hai-iin” but its spelt “hanni” for some reason.  It is similar to 原因　げんいん which means “cause” and is said “gay-in” but spelt “genninn”.

This one has been coming up a lot at work recently ( yeh, I am a programmer ) :

重複

ちょうふく

choufuku

And it means “duplicate”

I have seen it being used with “suru” so I guess what you say, for example, is  “the data is duplicating”
データが重複している。

でーたがちょうふくしている。

de-ta ga choufuku shiteiru.

There is some duplicate data

.. かもしらない

Added to the end of a sentence “ka mo shiranai” turns whatever you just said into a “perhaps”.

So if you say, “he is coming now” : 彼が今くる “kare ga ima kuru”

and then add “ka mo shiranai” : 彼が今くるかもしらない　”kare ga ima kuru ka mo shiranai”

then you can change the meaning to “he is probably coming now” or “he might be coming now”