Walk on the floor. Wood feels solid and unmoving underfoot. Laminate's foam underlayer gives it a softer, almost squishy feel.
Listen for clicking as you walk. The grooves where the boards snap together sometimes make a clicking sound if the floor is imperfectly installed.
Examine the lines between the boards. Wood flooring comes in individual slats. You can see and feel the seams where the boards adjoin. It's possible to purchase laminate in individual slats, but laminate floors typically come in wide planks that look like three boards joined together side-by-side. In place of cut edges butted together, the boards may have pictures of joint lines with no change in texture.
Evaluate the layout. Wood flooring has staggered boards in varying lengths. Laminate appears staggered at first glance, but since the boards come in just two sizes, the short ends of every other board line up all the way across the room.
Look at the seams. Wood slats lie flat, with no curling or warping unless the floor has been damaged. Laminate flooring, on the other hand, takes on a wavelike appearance when the installer fails to leave space at the perimeter of the room for the boards to expand. Thus, the adjoining short ends crowd together with enough force that they curl up slightly to form peaks.
Note the boards' grain and markings. No two wood floor boards are exactly alike. Laminate boards, on the other hand, have repetitive patterns. Same-size boards generally have the exact same patterns.
Look close-up at the surface texture. Wood has the natural texture you're accustomed to seeing in wood. Laminate may lack texture entirely -- it may be satiny smooth -- or texture may be too deep or too fine, so when viewed at an angle, under a bright light, it looks like textured plastic.