contraproducente, opposite to that desired.
contrariar, to oppose, annoy.
contrariedad, f., opposition.
contrari-o, -a, contrary, adverse.
contrario, m., contrary, opposite.
contratista, m., contractor.
contribuir, to contribute.
contribuyo, pres. of contribuir.
convalecencia, f., convalescence.
convencer, to convince.