Thank you, do you have a pronoun link?

Question

I have to decide if sentences have these

Pronoun shift in number
Pronoun shift in person
Ambiguous reference

Answer 1

http://www.grammarbook.com/grammar/pronoun.asp

http://owl.english.purdue.edu/owl/resource/595/01/

http://www.iolani.honolulu.hi.us/Keables/KeablesGuide/PartOne/Pronouns.htm

Answer 2

http://web.cn.edu/kwheeler/gram_pronoun_shifts.html

Answer 3

Lisa hoped that shelly had remembered to aks her mother for the chocolate chip cookies.

Pronoun shift in number
Pronoun shift in person
Ambiguous reference
No error