Every plant label says the same three words — bright, indirect light — and almost nobody's living room comes with a definition. Here is the greenhouse version, translated for real homes.
The shadow test
At midday, hold your hand a foot above the spot where the plant will live. A sharp, clear shadow means bright light. A soft, blurry shadow means medium light. Barely any shadow at all means low light — and that is fine, as long as the plant agrees.
Distance is a dimmer switch
Light drops fast as you move away from glass. A plant two metres from a south window is in medium light, not bright. A plant on the sill of a north window often gets more usable light than one across the room from a south window.
Match the plant to the reading
Bright: Bird of Paradise, Fiddle-Leaf Fig, Olive Tree. Medium: Monstera, Pothos, Peace Lily. Low: Snake Plant, ZZ Plant, Philodendron — all three will simply grow more slowly and ask for less water.
When in doubt, choose the plant for the light you have, not the light you plan to have. Plants are honest that way.