1. Stop at the red light.

Question

2. Stop on the red light.
(Which preposition should we use?)

3. Turn slightly right.
4. This is a one-way street.
(Are both grammatical?)

5. Fill it up with regular unleaded, please.
6. Fill her up with regular, please.
7. Fill it up with the unleaded.
(Are the three the same? Which one is commonly used? Thank you.)

Answer 1

#s 1, 3, 4, 5, and 7 are correct and commonly used.

#6 is used in a slangy way in some parts of the US!

If you use #2, people will understand you, but it's not used much at all.

Answer 2

Also -- I don't know of any gas stations that have attendants. All the stations I've seen are self-serve -- so 5-7 are useless.

Answer 3

There might be a few full-service stations left in Korea!

http://www.arirang.co.kr/News/News_View.asp?nseq=152490