Answer the following question given this paragraph: 

An amide can be formed by combining a carboxylic acid and an amine. Only primary and secondary amines can be used to form amides, since they have a hydrogen that can be replaced with the carbonyl carbon; tertiary amines will not form amides. The amide shown in the Figure above was formed from a carboxylic acid and a primary amine.


Q: What can be combined with an amine to form an amide?


A:
carboxylic acid