That's a good question. Basically, both tenses tell you that the action will happen in the future. If you simply want to state that the action will happen in the future ? you can use the simple present. This tense gives no other data than the time --> Future. The future progressive, however, tells you two things. 1) It tells you the time of the action --> Future 2) It tells you that the action will be IN PROGRESS. For example: "Tomorrow at nine o'clock I will be watching TV ? so don't call me." This sentence tells you that the action of watching will be IN PROGRESS at nine o'clock. In conclusion, if you would like to say that the action will happen ? you can use the simple future tense. If you would like to say that the action will happen, and you want to emphasize that it will be in progress at some time ? you can use the future progressive tense. So "I will leave tomorrow" and "I will be leaving tomorrow" do have a very similar meaning! However, the second one puts emphasis on the continuation of the action.

Fiona please see this: http://www.italki.com/groups/2002/topic/43746.htm You'll find all the answers there.

FUTURE SIMPLE: There a several forms. It is used to talk about something that will happen in a time after now. e.g. I will write a 'thank you' letter tomorrow. FUTURE CONTINUOUS: Used to refer to a future action that will be continuing. e.g. "Please don't call me between 2 and 4 on Saturday, because I'll be watching television! The big game starts at 2, and I don't want to miss any of it!"