Phrasal Verbs - check these sites out!

Phrasal Verbs. Always necessary. These sites are really useful:
http://www.sk.com.br/sk-twow.html 
http://www.englishclub.com/vocabulary/phrasal-verbs-list.htm 
http://www.learn-english-today.com/phrasal-verbs/phrasal-verb-list.htm
http://www.englishpage.com/prepositions/phrasaldictionary.html
And have fun! ;-)

Should Have + Past Participle

This grammar structure is very elegant when you express regret, something you shouldn' have done (but instead, you did it) or you should've done (but you didn't do). It's formed by:
the modal should + have + verb in the past participle
Examples:
- She should have told her parents the truth.
- They shouldn't have broken the computer.
- You should have woken earlier today.


On these links, you can do some exercises online: one from BBC and OUP, both are excellent.
Many students have huge difficulties about learning past participles, but there's no other way, you must memorize them. It's a question of practicing and reading a lot. Hope to have helped you all!