13. Yes, they must always be clean.
14. We want to study Spanish because it is (es) very necessary in commerce (en el comercio).
15. If you study with attention you will soon (pronto) speak and write Spanish very well.
16. John speaks French very badly but he is studying it (lo está estudiando) with much attention.
17. Do you understand this lesson?
18. Yes, I understand this lesson well; it is not very difficult.
19. No lesson is difficult if we study with care (con cuidado).
[Footnote 48: "Some" and "any," following a verb and referring to a singular noun previously mentioned, are not to be translated.]
[Footnote 49: "Some" and "any" are generally not translated when they are not used in a partitive sense, i.e., with an idea of a limited quantity.]
LESSON VI.
(Lección sexta.)