You can get hours of extra Grammar 3 practice. Here are links from other ESL websites. (Thank you to these ESL websites.) You may want to bookmark this page so you can come back to it again.
present perfect(See exercises at the bottom of the linked page.)
present perfect or simple past 1 (See exercises at the bottom of the linked page.))
present perfect vs. present perfect progressive 2 (See exercises at the bottom of the linked page.)
using present perfect progressive: correct or not
plural nouns (-s, -es and other spelling) (See exercises at the bottom of the linked page.)
review spelling of +s plurals
irregular plurals 1 (See exercises at the bottom of the linked page.)
count and noncount nouns (See exercises at the bottom of the linked page.)
review of count and noncount nouns with link to exercises - 1
review of count and noncount nouns with link to exercises - 2
count and noncount quantifiers (some, a little, a few, etc.)
S + V agreement with prepositional phrases and clauses (See exercises at the bottom of the linked page.)
one of / some of (exercises at the bottom)
special nouns: news, the poor, etc.(See exercises at the bottom of the linked page.)
a difficult quiz (Try if you want a challenge!)
review of active / passive based on first Indiana Jones movies
participles –ed/-ing (See exercises at the bottom of the linked page.)