1. You don't have to go there.

2. You have not to go there.
(In British English, is #2 the same as #1?)

3. There were five men in the room. One was old and the others were young.

4. There were five men in the room: One was old and the others were young.

5. There were five men in the room; One was old and the others were young.
(There are two sentences in #3. In #4, a colon was used. In #5, a semi-colon was used. Can we use the three types? Are they all grammatical?)

1 is correct word order.

2 was probably correct word order for Shakespeare in the 1600s!

Both 3 and 4 are correct. 4 is slightly better since 4 explains 3, thus the colon.

5 will be correct once you use a lower-case "o" after the semicolon.

1. In British English, sentence #1 "You don't have to go there" and sentence #2 "You have not to go there" have the same meaning. Both sentences express the idea that going there is not necessary.

2. The three sentences in #3, #4, and #5 can all be grammatically correct but have slightly different punctuation and structure.

- Sentence #3: "There were five men in the room. One was old and the others were young." These are two separate sentences that describe the five men in the room. They can stand on their own and convey complete thoughts.
- Sentence #4: "There were five men in the room: One was old and the others were young." Here, a colon is used to introduce the description of the five men. The colon is used to indicate that what follows the colon expands or clarifies what was mentioned before it.
- Sentence #5: "There were five men in the room; One was old and the others were young." In this case, a semi-colon is used to separate the two statements about the five men. The semi-colon is used to connect two independent but related clauses.

So, while all three forms are grammatically acceptable, the choice of punctuation can depend on the specific style or preference of the writer.