Final answer:
The subject pronoun that is only used in Spain is vosotros. It is the plural form of 'you' when talking to a group of people.
Step-by-step explanation:
The subject pronoun that is only used in Spain is vosotros.
In Spanish, subject pronouns are used to represent the subjects of sentences. While most Spanish-speaking countries use the subject pronoun tú to mean 'you' when talking to one person, vosotros is only used in Spain and is the plural form of 'you' when talking to a group of people.
For example, if you were addressing a group of friends in Spain, you would say '¿Vosotros estáis bien?' meaning 'Are you all alright?'
Learn more about Spanish subject pronouns