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.
Sentences 1, 3, and 4 are correct.
In the original of sentence 2, are there any quotation marks, too?
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.
In the provided sentences, colons are used to introduce a list of items or to separate the introduction from the information that follows. Here's an explanation for each sentence:
1. "The special exhibit on birds contains the following types: prehistoric birds, seabirds, and domestic birds."
- In this sentence, the colon is used to introduce a list of types of birds that are included in the special exhibit. The types listed after the colon are the prehistoric birds, seabirds, and domestic birds.
2. "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."
- Here, the colon is used to separate the salutation (Dear Sir) from the main body of the letter. It is commonly used in formal letter writing to introduce the main message after the greeting.
3. "He told us that we could find out more about the following kinds of penguins: the Emperor, the Adelie, and the Magellan."
- In this sentence, the colon is used to introduce a list of specific kinds of penguins. The kinds of penguins listed after the colon are the Emperor, the Adelie, and the Magellan.
4. "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."
- In this sentence, the colon is used to separate the cause (being afraid of not being ready to leave) from the effect (the museum closing at 3:30). It helps to show the reason or explanation for the statement made before the colon.