ESL: Subjunctive in Adverbial Clauses: Spanish and English

http://users.ipfw.edu/jehle/courses/SUBJADV.HTM The subjunctive in adverbial clauses

A great site for bilingual Spanish students who are trying to understand English grammar. This site is basically in English but explains the English within a Spanish context. For example:

" If no change of subject is involved and a preposition exists which corresponds to the conjunction, that preposition plus an infinitive is normally used, e.g.: He's saving his money so he can buy a car, Ahorra su dinero para poder comprar un coche. "