1. We have to discuss gender discrimination.

2. In French the adjective must agree with the noun in number and gender.
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In each sentence, can we use 'sex' instead of 'gender'?

For sentence 2, no.

For sentence 1, you'd need to use the adjective form: sexual.

To answer your question, we need to understand the difference between "gender" and "sex" and how they are used in different contexts.

1. "Gender discrimination" specifically refers to the unjust treatment of individuals based on their gender identity. Gender is a complex concept that encompasses social, cultural, and psychological aspects of identity, whereas sex refers to biological characteristics such as male or female reproductive organs. Therefore, using "sex discrimination" may not accurately convey the broader social and cultural dimensions associated with gender discrimination.

2. In French, the adjective must agree with the noun in both number (singular or plural) and gender (masculine or feminine). Here, "gender" is the appropriate term because it relates to grammatical gender in the French language. It does not refer to societal or individual gender identity, as it would in the context of gender discrimination.

In summary, while "sex" may sometimes be used interchangeably with "gender" in colloquial English, it is important to recognize that they have distinct meanings and should be used appropriately in different contexts.