block : 语气强烈，指有效堵住了通道，使人或物无法通过。
- A fallen tree is blocking the road.
- As she left the court, an angry crowd tried to block her way.
bar : 含义与block很接近，指阻塞通道或禁止出入，但有对暗示不用障碍物的阻止或禁止。
- The centre of the town was barred to football supporters.
- The incident led to him being barred from the country/barred from entering the country.
- I tried to push past her but she barred my way/path (= stood in front of me and prevented me from getting past).
hinder : 语气较轻，多指阻碍、拖延人或事，强调使进展速度缓慢下来。
- High winds have hindered firefighters in their efforts to put out the blaze.
- Her progress certainly hasn't been hindered by her lack of experience.
obstruct : 正式用词，语气强，多指以干扰或设置障碍的方式阻碍交通，使不能自由畅通。
- After the earthquake many roads were obstructed by collapsed buildings.
- Her view of the stage was obstructed by a pillar.
- An accident is obstructing traffic on the M11.
- to obstruct a police investigation
- He got five years in prison for withholding evidence and obstructing the course of justice.
- He was charged with obstructing justice.
prevent : 含义广泛，指采取预防措施或设置障碍去阻止某人或某事。
- Label your suitcases to prevent confusion.
- His disability prevents him (from) driving.
hamper : 侧重因受到约束或阻碍而造成的行动困难。
- Fierce storms have been hampering rescue efforts and there is now little chance of finding more survivors.