by/in cash

English as a Second Language English Vocabulary, Grammar and Idioms
1

1a. Wages/Salaries were paid by cash.
1b. Wages/Salaries were paid in cash.
2a. You have to pay by cash.
2b. You have to pay in cash.
Please check and correct. Thanks.

2

1b and 2b are correct.

3

According to some English grammar books, both “pay in cash” and “pay cash” are possible. Thus, are the following sentences also correct?

1c. Wages/Salaries were paid cash.
2c. You have to pay cash.

    Thanks.
4

1c is not possible. It sounds as if the wages themselves are being paid cash for something, rather than the wage earners receiving payment in cash.