Verse

e|-----------------|
B|-----------------|
G|--9--------------|       Play this everytime u hear guitar in the verse
D|--9--------------|
A|--7--------------|
E|-----------------|

Pre-chorus

e|------------------------------------------------------------------------|
B|------------------------------------------------------------------------|
G|--9---7---5---5---------------------------------------------------------|
D|--9---7---5---5---------------------------------------------------------| X2
A|--7---5---3---3---------------------------------------------------------|
E|------------------------------------------------------------------------|


Chorus


e|-------------------|-------------------------------------|------------------|
B|-------------------|-------------------------------------|------------------|
G|--9-----7-----5----|---14P-12-14-12----------------------|------------------|
D|--9 X 8--7 X 8--5 X16-|---------------14-12-14-12-----------| X2------------|X2
A|--7-----5-----3----|--------------------------14-12-14-12|------------------|
E|-------------------|-------------------------------------|------------------|

Just keep repeating this for an example you can watch this its very easy 
http://www.youtube.com/watch?v=25EoTEuGGfU