How To Write A Proper Letter In Spanish . Spanish grammar, spanish listening, spanish reading, spanish speaking, spanish writing, spanish vocabulary and mexican culture knowledge. / ms.) muy señores mÃos: Better letters and formal Spanish formations from thebogotapost.com Within the main section you would use formal language, so you would use the verbs in the usted/ustedes form (3rd person endings), rather than tú/vuestro form. (dear sir or madam) estimado(a) sr. 2 add the spanish language to the list of recognized languages for input words.