Hi,
I’m getting curious about these two everyday expressions:
Pay in cach and pay by check.
I feel that it’s yet tolerable to say ‘pay by cash’ but not to say ‘pay in check’.
Could you please tell me why ‘in cach’ but ‘by check’? Or they are just idiometic?
Thank you!
Haihao
.
I’d say (for want of a brainstorm) that the usage is idiomatic: ‘pay in cash’; ‘pay by check’; ‘pay by credit card’. '‘Pay with a check/with my credit card/with cash’.
A googling, out of curiosity:
176,000 English pages for “pay with cash”.
612,000 English pages for “pay in cash”
275,000 English pages for “pay by cash”
1,220,000 English pages for “pay by check”
1,430 English pages for “pay in check”
Whatever else holds true, evidently the check is the more popular instrument!
.
‘evidently the check is the more popular instrument!’ comforts me satisfactorily, Mr. Micawber. 
How many of these Google results were on pages from English-speaking countries, and how many were written by non-native speakers? “Pay by cash” sounds like foreigner English to my fallible ears.
.
There is no shame in fallibility, Jamie. Let us know how your research on website origins goes.
.
Just to add my two pence worth: ‘pay cash’, i.e. without preposition, is a very common way of saying it.
Whereas pay check is something way off what was talked about here and always very welcome by me. 
Hi,
And now a euro’s worth (Oh how I wish we in the UK used the euro!); That’ll be a cash payment.
A
I’ve always used “pay in cash” and “pay by check” i don’t know why , it seems natural to me…
I don’t want to pursue a dispute of the euro issue or even accuse you of deluding yourself, but if you used the euro in the UK, I assume you wouldn’t be too euphoric (view it as a pure euphemism) at first, as you’d need to get used to the unusual, unique, uniform, unifying, singular, not too alluring and sometimes abused currency unit of the European Union (phew!).
My immune view on the soluble issue might be inaccurate and refutable, but it hopefully won’t raise an acute hue and cry in unison.
A bird duly and dutifully singing its heart out…