1. She sent Ben a letter.

Question

2. She sent Ben a postcard.
(Does #2 mean #1?)

3. Pretend you have been a frozen man for 20 years. You woke up just now. What are your plans for the future? I want to take exercise first. I plan to deliver a speech at a conference. I hope to see my girl friend.
(Is this passage grammatical? Would you check the errors? Thank you.)

Answer 1

A postcard is an open-faced correspondence, while a letter can be much longer and is typically enclosed in an envelope, so #2 does not mean #1.

Delete "take" in first sentence. It would be more specific to indicate the topic of your speech and the type of conference. By seeing your girl friend, does this mean attempting to re-establishing the relationship again? Although you have essentially remained static over two decades, her life has probably changed dramatically. Think about it.

Answer 2

#1 and #2 are different.

Letters are written on pieces of paper and then put in envelopes for mailing.
http://www.google.com/search?q=letter+and+envelope&es_sm=119&tbm=isch&tbo=u&source=univ&sa=X&ei=wUgBVLKIG-30iwLnyICwDg&ved=0CC8QsAQ&biw=1440&bih=707

Postcards are heavier paper, cut small, and mailed without the need for an envelope.
http://www.google.com/search?q=postcards&es_sm=119&source=lnms&tbm=isch&sa=X&ei=9EgBVKyVKcm7ogTiaw&ved=0CAgQ_AUoAQ&biw=1440&bih=707

I'd make a few minor changes in #3.
Pretend you have been frozen for 20 years. Now that you have awakened, what are your plans for the future? ...