Personal a, going to, Irregular yo forms

Personal a

Remember that when you use the verb oir, if you hear a person, you will add an a or personal a. The same happens with the verb conocer (to know) and ver (to see, watch)

http://www.studyspanish.com/practice/persa.htm
http://www.quia.com/pop/36367.html

Going to
http://www.quia.com/rr/533673.html
http://www.quia.com/rr/93710.html
http://www.quia.com/quiz/932833.html
http://www.studyspanish.com/practice/ira.htm

Irregular yo forms
http://www.trinity.edu/MSTROUD/GRAMMAR/p4a.html