Take a pencil and paper and get crackin' !
I hope that's good motivation for you!
Iambic pentameter. this is to further explain---"and sum/ mers lease/ hath all/ too short/ a date"
penta means 5, there for after you divde the sonnet up as its said youll see that there are only 5 "meters"
The answer is subcordinate
The way i do it is cover up the other words and read the underlined part alone and see if it makes sense