- ser - It is used to attribute to the subject of the sentence an intrinsic, natural or permanent quality or condition, which is expressed through an adjective, a prepositional complement, a name or an equivalent sentence; It is also used to indicate the trade or profession that a person has or some habitual activity or dedication. "He is single"
-estar-
It is used to attribute to the subject of the sentence a quality or a non-permanent characteristic or the result of an action or process, which is expressed by an adjective, a participle or an equivalent sentence. "be happy"
11. Las vacas están en el campo. 13. Estos zapatos son de China. 15. Las playas de México son bonitas. 17. Las hermanas están muy cansadas. 18. Son las ocho y cuarto.
12. I used estar because in this sentence the cows are in a location therefore estar is used here. I used the present tense of to eat to match estar.
13.Estos zapatos que vienen son de China.
14. I used ser because it is talking about the shoes that will always be form china. It is in a permament stae so ser is used here. i used the verb to come because it matches the present tense.
