Pems to the left, Cardis to the right! How can you tell the difference between a Pembroke and a Cardigan? I can tell you for certain, using google does not provide reliable results. One of those Pems even came from a breed profile for Cardis!
Pembrokes tend to have finer, more tapered heads, while Cardigans will have a coarser muzzle and square jaw, as well as overall thicker bone structure.
Cardis will always have a tail - not all Pems are without tail, but if it’s docked, it’s definitely a Pem.
Pems come in shades of red, as well as sable (shaded or saddle-marked) and black with tan points. Cardis also come in these colours, but all others are strictly Cardigan: black, brindle, and anything merle.
You are now free to lord your corgi-discerning abilities over others!