Am
e|-----------------------------------------|
B|------0-0-0h1-1-1-1p0-0-0-0h1-1-1-1p0-0--|
G|--2-2----2-------2-------2-------2-----2-|
D|---2-2-2-------2-------2-------2-----2---|
A|-0---------------------------------------|
E|-----------------------------------------|
F
e|-----------------------------------------|
B|------0---0h1-1-1-1p0-0-0-0h1-1-1-1------|
G|--2-2---2--------2-------2-------2-------|
D|-3-3-3-3-3-----3-------3-------3---------|
A|-----------------------------------------|
E|-----------------------------------------|
[ Tab from: https://www.guitartabs.cc/tabs/f/freddie_aguilar/anak_tab_ver_2.html ]
G
e|-----------------------------------------|
B|----0----1-0---0-------------------------|
G|--0----0-----2---------------------------|
D|---0--0-0--------------------------------|
A|-----------------------------------------|
E|-3---------------------------------------|
Once the G column finishes it goes back to the Am column...
Intro=Am,F,G
Verse=C,G,Am,F,G,Am
Chorus=Am,F,G
Throughout the song the Am chord is played with the B-string at fret 1 and 0 alternatively...