Hi, theres no doubt that these can be quite confusing.... the best way to think of within is by imagining a period of time and what happens within that period. "within one month I will go to China" It can also be used where there are set boundaries such as "within these walls" or "the enemy within". Its more poetic. "inside" is the same but does not give the same feeling of certainity or confinement. it merely refers to something which is inside a certain box, place or room. "the enemy inside" "inside these walls" inside is not generally used with time. "In" is very informal and can be used to denote one thing in another... "In the room, In the suitcase." with time, In can be used to form the future tense." In one month I will go to China."

Oh,I think in most cases you can use any one of them.

regarder ce site Web: http://dictionary.reverso.net/english-french/inside