GrassFairy
Grass/Fairy weaknesses
Grass/Fairy is weak to Poison, Fire, Ice, Flying and Steel, and takes 4× from Poison.
When Grass/Fairy Pokémon are hit
4×Hits hardest
2×Super effective
½×Not very effective
0×No effect
Its two types separately
Multiply the two to get the result. For example, Poison deals 2× × 2× = 4×.