kal, kalj both exists
gal, galj both exist
mal(en), malj(en)…
pal(en), palj(en)…

kal = gal in meaning, black like sooth, like charcoal, like raven, crow, jackdaw…

k and g are interchangeable sounds which depend on dialect and pronunciation abilities, and so are l and lj

Ingva common sense and imagination (remember that word) is something you can't learn. You can learn every book you read by heart, it won't help you to solve problems. For that you need imagination and common sense.