allow and let mean the same (maybe let is less formal). However, let has no passive form, so allow should be used instead. let somebody do something Somebody is allowed to do something hope it helps

the meaning of both words, as you know, are similar. However, Allow is more formal and is more of an expression of authority: "You are not allowed in here", "I will allow you to park your car here". Let is a more informal way of saying the same thing: "they do not let you in here", "I'll let you park here". Very subtle difference between them really.