-I sell equipments through phone and mail (equipment needs to be single, not plural. its a noun which is already plural) -We do a lot of speaking (correct) -We determine the needs of the customer to propose the most suitable equipment (correct) -We manage the administration to ensure the follow-up after the sale (correct) These are all correct, but if you are aiming for a more business language then we can change them to make them more "business like" I sell equipment by phone and email (I assume email because its like, 2019, but you may be doing it by paper mail) regular customer interactions by phone (sounds a bit more business like) Individual consultations to identify customers needs and suitable equipment requirments to satisfy those needs (very business like) After sales service management to ensure customer satisfaction There you go. Your English was good... but not as "business" as it could be. I think this should be ok for a job description.

INCORRECT: "Describing a job profile who works as a Business commercial" A commercial is an advertisement. I think what you mean is: Describing a job profile for someone who works as a commercial businessman. (Here, 'commercial' is used as an adjective.) CORRECT: I sell equipment by phone and mail. (Mail or email?) We do a lot of speaking. (Grammatically correct, but what does it mean exactly?) We determine the needs of the customer in order to recommend the most suitable equipment. We follow up with the customer after the sale. / Our company provides customer follow-up/support after the sale.