Verbs

https://drive.google.com/file/d/0B-2fvJUBid2yN043V1NIN05PQm8/view?usp=sharing

https://drive.google.com/file/d/0B-2fvJUBid2yVldfTEJEOGthVm8/view?usp=sharing

http://www.perfect-english-grammar.com/present-perfect-use.html

http://esl.fis.edu/grammar/rules/future.htm

http://grammar.yourdictionary.com/parts-of-speech/verbs/subject-verb-agreement-worksheet.html 
 
https://owl.english.purdue.edu/exercises/5/13/34