Sentences 1, 3, and 4 are correct.
In the original of sentence 2, are there any quotation marks, too?
Using colons
The special exhibit on birds contains the following types: prehistoric birds, seabirds, and domestic birds.
The letter we wrote to the museum began Dear Sir: Please let us know when the special exhibition on penguins will be shown at your museum.
He told us that we could find out more about the following kinds of penguins: the Emperor, the Adelie, and the Magellan.
We were afraid there would be so much to see that we wouldn't be ready to leave at 3:30 when the museum closed.
3 answers
In the original of sentence 2 there are no quotation marks
Sentence 2 reads funny without quotation marks. The colon after "Sir" is correct IF you're writing a formal business letter, but to include this phrasing in a regular sentence, there should be quotation marks.
I guess you should go with what you have, but I still think it reads funny.
I guess you should go with what you have, but I still think it reads funny.