(Are you going to pay by) credit or debit?
>> Você vai pagar em crédito ou débito?(Are you going to pay with a) credit or debit card?
>> Você vai pagar com um cartão de crédito ou débito?(Are you going to pay (in)) cash or charge?
>> Você vai pagar com dinheiro ou cartão?
There seems to be an entire family of expressions involving pay + [form of money]
that permit English speakers to use either pay [form of money]
or pay in [form of money]
To pay cash = to pay in cash.
To pay hard currency = to pay in hard currency;
To pay dollars = to pay in dollars;
To pay ready money = to pay in ready money;
To pay silver = pay in silver.
The dual acceptability seems to break down in situations where English speakers would normally use by
in place of in
To pay by check /cheque;to pay check/cheque
To pay by credit card; to pay credit card
The first set of phrases remain idiomatically acceptable (in U.S. English, anyway) when you substitute in
To pay with cash;
To pay with hard currency;
To pay with dollars;
To pay with ready money;
To pay with silver.
In contrast, substituting with
in the second group works only if you add an indefinite article after with:
To pay with a check/cheque;
To pay with a credit card.
I believe the underlying distinction at work here may be the difference between form of payment (cash, hard currency, dollars, etc.) and mode of transfer (check/cheque, credit card).
(2) Oxford Learner's Dictionary.
(3) BENNETT, David C. Spatial and Temporal Uses of English Prepositions: An Essay in Stratificational Semantics
. London: Longman. 1975.
(4) KOOPMAN, Hilda. Prepositions, postpositions, circumpositions, and particles
. In: The Syntax of Specifiers and Heads
. London: Routledge, 2000.