Thank you very much for your last corrections.

Here are some more sentences about Christmas holidays I would like you to check.
1) How long did your Chrismas holidays last?
2) How long did it take you to eat your Christmas lunch? OR How much time (How long) did you spend eating your Christmas lunch?
3) Where did you stay in the mountains?
4) Who did you stay in the mountains with? Have you got a second-holiday home in the mountains?
5) How often did you eat at the restaurant during your holidays?
How much did it cost to eat at the restaurant? OR How much did you spend on your Christmas lunch at the restaurant?
6) How much money did you spend on your presents?
7) Who did you invite to your party?
8)Did you use up all your pocket money?
What did you receive as a Christmas present from your parents?
9)What did your best friend give you as a Christmas present?
10)How long did it take you to dress the Christmas tree?
11) Did you go anywhere interesting? 12) Did you go sightseeing? Did you take any pictures? Did you make any new friends?
13)What food did you eat the most often during your Christmas holidays?
14) What did your Christmas lunch constist of? How was it?OR What did you have for Christmas lunch OR for lunch on Christmas Day???
8) What food did you like the best? What did you have for your starter?
What did you have to drink?
9) What food did your mother cook the best?
10) When was the last time you ate at the restaurant? OR When did you last eat at the restaurant?
11)What did you help your mum with (OR to do?)
12) What does your father do as a job?
13) What time did you leave for the seaside/mountains?
14) How long did you take to do your holiday homework? Did your teachers give (or set?) you a lot of homework?
15) Did you get any help to do it?

Thank you very much

4. Who is the subject but in this sentence you is the subject. Whom is the objective case and that's what you need here. It's best to NOT end a sentence with a preposition. Who did you stay in the mountains with? = With whom did you stay in the mountains?

7. Same type of error as #4 with who/whom. Who did you invite to your party? = Whom did you invite...

14. (or set?) = no, don't use that

Everything else looks good!

Sra

Here are the corrected sentences:

1) How long did your Christmas holidays last?
2) How long did it take you to eat your Christmas lunch? OR How much time did you spend eating your Christmas lunch?
3) Where did you stay in the mountains?
4) Who did you stay with in the mountains? Do you have a second holiday home in the mountains?
5) How often did you eat at the restaurant during your holidays? How much did it cost to eat at the restaurant? OR How much did you spend on your Christmas lunch at the restaurant?
6) How much money did you spend on your presents?
7) Who did you invite to your party?
8) Did you use up all your pocket money? What did you receive as a Christmas present from your parents?
9) What did your best friend give you as a Christmas present?
10) How long did it take you to decorate the Christmas tree?
11) Did you visit any interesting places? 12) Did you go sightseeing? Did you take any pictures? Did you make any new friends?
13) What food did you eat the most during your Christmas holidays?
14) What did your Christmas lunch consist of? How was it? OR What did you have for Christmas lunch? OR What did you have for lunch on Christmas Day?
15) What food did you like the best? What did you have for your starter? What did you have to drink?
16) What food does your mother cook the best?
17) When was the last time you ate at the restaurant? OR When did you last eat at the restaurant?
18) What did you help your mom with (OR help her do)?
19) What does your father do for a living?
20) What time did you leave for the seaside/mountains?
21) How long did it take you to complete your holiday homework? Did your teachers give you a lot of homework?
22) Did you receive any help to complete it?

You're welcome! If you have any more sentences or questions, feel free to ask.