Utilizar de forma acertada el auxiliar "do".
GRAMMAR
Forming the simple past tense (Regular verbs)
http://web2.uvcs.uvic.ca/elc/studyzone/330/grammar/pasted.htm
Forming the simple past tense (Irregular verbs)
http://web2.uvcs.uvic.ca/elc/studyzone/330/grammar/irpast.htm
Negatives and questions in the simple past tense
http://web2.uvcs.uvic.ca/elc/studyzone/330/grammar/pastnq.htm
VOCABULARY
Possessives
http://pagesperso-orange.fr/michel.barbot/cap/adj_poss/poss1.htm
http://web2.uvcs.uvic.ca/elc/studyzone/410/grammar/poss1.htm
READING SKILL
WHAT'S A SENTENCE (Game)
http://www.bbc.co.uk/skillswise/words/grammar/sentencebasics/whatisasentence/game.shtml
THE STRUCTURE OF A SENTENCE
(The simple sentence: My friend invited me to a party. I do not want to go.
The compound sentence: My friend invited me to a party, but I do not want to go
The complex sentence: Although my friend invited me to a party, I do not want to go
http://www.uottawa.ca/academic/arts/writcent/hypergrammar/sntstrct.html#simple%20sentence
