Links a temas gramaticales: Passive Voice, Relative Clauses and Perfect Tenses

A lot on information!

Passive Voice

http://www.youtube.com/watch?v=pxbQ2U3Uuv0

http://www.youtube.com/watch?v=QTQb42w7oig

http://www.youtube.com/watch?v=g72m8wyNzsI

http://www.youtube.com/watch?v=g72m8wyNzsI

http://www.youtube.com/watch?v=1xTreaklNr8

http://www.youtube.com/watch?v=ePfmgMTgXl8

http://www.youtube.com/watch?v=WNk4q3K2CFM

Relative clauses

http://www.youtube.com/watch?v=5rV6EY1Zqis

http://www.youtube.com/watch?v=_lBL3GlImGA (explicación en español)

Present perfect tense

http://www.youtube.com/watch?v=rIVU4svh_Og

http://www.youtube.com/watch?v=Dkln8PfE1xE 

http://www.youtube.com/watch?v=5vJOJrVIgek 

http://www.youtube.com/watch?v=FUGy9J_9cvg  

Past perfect tense 

http://www.youtube.com/watch?v=XjS8xPRtjlc

http://www.youtube.com/watch?v=xPtqcXlrDMw 

http://www.youtube.com/watch?v=i1AoNsObnXk

Comparative and Superlative adjectives
http://www.onestopenglish.com/grammar/grammar-reference/adjectives/comparative-and-superlative-adjectives-article/144846.article