A lot of learners can recognize a sign but can't say what category it belongs to, and that distinction is exactly what some questions are testing.
Here is one worth locking in:
What shape and color tells you a sign is a command you must obey, versus one that's just warning you of a hazard ahead?
Regulatory signs are typically circular and carry a legal obligation, ignoring them is an offence, while warning signs are usually triangular and inform you of a condition ahead, like a bend or a school zone, without a direct command attached. Mixing up "must obey" with "should be aware of" is a common way this gets marked wrong.
Beyond shape and color, this category also covers how signs combine with road markings to reinforce the same rule.
Your turn. If there is a sign category you keep mixing up, post it here. If you know the answer to someone else's, help them out.
