intro/verse:

e---0-----0-----0---------------------------|
b-----1-----1-------------------------------|
g-------------0-----------------------------|
d-2-----3-----------------------------------|
a-------------------------------------------|
E-------------------------------------------|

pre chorus:

e---------------------------------|
b-1---0-1-3-3-1-0-1---0-1-3-------|
g---0---------------0-------------|
d---------------------------------|
a---------------------------------|
E---------------------------------|

chorus:

e----0-------0---------0------0-----0--------|
b------1--------1--------1------1------------|
g--0-------0---------0------------0----------|
d------------------2--------3----------------|
a-3------2-----------------------------------|
E--------------------------------------------|

then on the 2nd chorus he adds only on the 2nd and 4th time.

e----3-------3---------3------0-----0--------|
b------1--------1--------1------1------------|
g--0-------0---------0------------0----------|
d------------------2--------3----------------|
a-3------2-----------------------------------|
E--------------------------------------------|

after the breakdown:

e----3-------3---------3------0-------------|
b------1--------1--------1------1------3----|
g--0-------0---------0-------------2/4------|
d------------------2--------3---------------|
a-3------2----------------------------------|
E-------------------------------------------|
thats it.listen to the song and ull see what i mean.
chords:

intro-Am,f,g x4
Verse:Am,f
pre chorus:f,g x2
chorus:c,g,Am,f,g