It's pretty easy. Hard part's sounding as good as Adele singing it :P
I tabbed it like I hear it. Enjoy!

Standard Tuning.

CAPO on 2 (Finger placings relative to capo)


INTRO & VERSE:
    G                                  G/Gb
||------------------------------------------------------------------------|
||------3-------3-------3-------3----------3-------3-------3-------3------|
||----4---4---4---4---4---4---4---4------4---4---4---4---4---4---4---4----|
||------------------------------------------------------------------------|
||------------------------------------------------------------------------|
||--3-------3-------3-------3----------2-------2-------2-------2----------|

   Em                                  C
||------0-------0-------0-------0----------0-------0-------0-------0------|
||--------0-------0-------0-------0------1---1---1---1---1---1---1---1----|
||----0-------0-------0-------0-------------------------------------------|
||------------------------------------------------------------------------|
||-------------------------------------3-------3-------3-------3----------|
||--0-------0-------0-------0---------------------------------------------|


PRE-CHORUS:
    D               Em                C
||------------------------------------------------------------------------|
||------3-------3-------3-------3---------1------ -1--------1--------1----|
||----0---0---0---0---0---0---0---0-----0---0----0---0----0---0----0---0--|
||--2-------2-------2------2----------------------------------------------|
||------------------------------------3--------3--------3--------3--------|
||------------------------------------------------------------------------|


CHORUS:
    G                 G/Gb              Em                C
||-----3-------3---------3--------3---------3-------3---------3-------3---|
||---3---3---3---3-----3---3----3---3---------3-------3-----3---3---3---3-|
||----------------------------------------0-------0-----------------------|
||--------------------------------------2-------2-------------------------| x3
||--------------------------------------------------------3-------3-------|
||-3-------3---------2--------2-------------------------------------------|

||-----3-------3---------3--------3---------0--------0--------3-------3---|
||---3---3---3---3-----3---3----3---3---------0--------0----1---1---1---1-|
||----------------------------------------0--------0----------------------|
||------------------------------------------------------------------------|
||--------------------------------------------------------3-------3-------|
||-3-------3---------2--------2---------0--------0------------------------|

||------------------------------------------0--------0--------3-------3---|
||-----3-------3------ --3--------3-----------0--------0----1---1---1---1-|
||---4---3---4---4--- -4---4----4---4-----0--------0----------------------|
||------------------------------------------------------------------------|
||--------------------------------------------------------3-------3-------|
||-3-------3---------2--------2---------0--------0------------------------|


BRIDGE:
  D/F#                                  Em
||------------------------------------------0-------0---------0--------0---|
||-----3--------3--------3--------3-------0---0----0---0----0---0----0---0-|
||---4---4----4---4----4---4----4---4--------------------------------------|
||-------------------------------------------------------------------------|
||-------------------------------------------------------------------------|
||-2--------2--------2--------2---------0--------0--------0--------0-------|
   Nothing compares ......              Regrets and mistakes...

   C                                   Am                Bm
||-----3--------3--------3-------3---------3--------3--------2--------2----|
||-------3--------3--------3-------3-----1---1----1---1----3---3----3---3--|
||---0--------0--------0--------0------------------------------------------|
||-------------------------------------------------------------------------|
||-3--------3--------3--------3--------0--------0--------2--------2--------|
||-------------------------------------------------------------------------|
  Who would have known how     bitter- sweet             this would

  C                 D
||-----3--------3--------5--------5-----|
||---3---3----3---3----3---3----3---3---|
||--------------------------------------|
||-------------------0--------0---------|
||-3--------3---------------------------|
||--------------------------------------|
   taste....