Dear Ellen,
Hello from Amsterdam! The weather . . . (be) sunny and I . . . (have) a fantastic time. David and I . . . (stay) at a lovely hotel in the city centre. We . . . (be) here since Tuesday and we . . . (already/ do) many interesting things.
We . . . (take) a boat trip down the Amstel River. We . . . (do) that on Wednesday. It . .. (be) amazing! We . . . (also/ visit) the Van Gogh Museum. We . . . (visit) it on Thursday. The paintings . . . (be) fascinating. I . . . (buy) some great posters there.
There are a lot of things we . . . (not / do) yet. We . . . (not/visit) the Anne Frank House and we . . . (not/go) to the Artis Zoo. We . . . (visit) the zoo tomorrow to see the animals. We . .. (also/visit) the Stedelijk Museum. It . . . (be) famous for its large collection of modern art.
Amsterdam . . . (be) a magnificent city – you must see it one day. We . . . (return) to New York on the 15th, so I . . . (see) you then.

is, have, stay, are, have already done, took, did, was, have also visited, visited, were, have bought, haven't done, didn't visit, didn't go, will visit, will also visit, is, is, will return, will see.