Perfect Modal Verbs </SPAN>
modal verb + have + past participle
Perfect Modal </STRONG></SPAN>
</STRONG>
Picture</STRONG></SPAN>
sentence</STRONG></SPAN>
could have
couldn't have
past ability
The boy could have done</STRONG> the dishes himself, but his father decided to help. </SPAN>
should have
shouldn't have
You did or didn't do something that was a good idea. </SPAN>
http://www.learnamericanenglishonlin...rl%20dizzy.jpgThe girl shouldn't have spun</STRONG> around so many times. She fell down.
spin: turn around many times.
spin / spun / spun
would have
wouldn't have
past condition /
past situation
This house of cards would have fallen</STRONG> over if the person who built it hadn't been so careful. </SPAN>
may have
may not have
past possibility
My grandfather may have used</STRONG> this camera when he was a young man, but I'm not sure. </SPAN>
might have
might not have
past possibility
Her mother might have put</STRONG> mustard on her sandwich. She hopes not. </SPAN>
must have
must not have
past probability
This indicates that something probably happened in the past
They must have practiced </STRONG>a lot because they're very good musicians. </SPAN>
Let's not forget
The Future Perfect Tense
Unlike all the other modals above, will is used for the future:
Subject + will + have + past participle
Singular</SPAN>
Plural
I will have lived </SPAN>
We will have lived </STRONG>
You will have lived </SPAN>
You will have lived </STRONG>
He will have lived </SPAN>
</SPAN>
She will have lived </SPAN>
They will have lived </STRONG>
It will have lived </SPAN>
</SPAN>
This is a difficult tense to use. It describes an action that will be completed in the future
For example
I moved to Minnesota in 1991. The year now is 2008
By 2011, I will have lived in Minnesota for 20 years
