Are there any grammatical mistakes?

6.Due to the nasty weather, I had to stay at my friend’s house.
7.If you are ever passing my house, do not forget to drop in for a cup of tea.
8.I locked myself out of the dormitory and thus I have to ask for accommodation officer’s help.
9. My mom cured her renal calculi (kidney stone) by the way of using stairs and drinking a lot of water.
10.Climbing up stairs is a good way to lose weight.
11.When I was a child, I had fallen down the stairs and I have a deep fear of that memory.
12.Running up and down the stairs is hard for an old people.
13.A flight of stairs needs to be repaired.
14.I put my camera at the foot of the stairs for convenience.
15.I climbed to the head of the stairs and shouted like a child.

Question

Are there any grammatical mistakes?

6.Due to the nasty weather, I had to stay at my friend’s house.
7.If you are ever passing my house, do not forget to drop in for a cup of tea.
8.I locked myself out of the dormitory and thus I have to ask for accommodation officer’s help.
9. My mom cured her renal calculi (kidney stone) by the way of using stairs and drinking a lot of water.
10.Climbing up stairs is a good way to lose weight.
11.When I was a child, I had fallen down the stairs and I have a deep fear of that memory.
12.Running up and down the stairs is hard for an old people.
13.A flight of stairs needs to be repaired.
14.I put my camera at the foot of the stairs for convenience.
15.I climbed to the head of the stairs and shouted like a child.

nitishatewatia · Accepted Answer

@Mapleer 
No grammatical mistakes found in sentences 6 to 15.
However, you may consider changing "renal calculi" to "kidney stones" in sentence 9 for clarity.

Hunky-dory · Answer

6. Due to the nasty weather, I had to stay at my friend’s house.
7. If you're ever passing my house, be sure and drop in for a cup of tea.
8.I locked myself out of the dormitory, and so I had to ask the accommodations officer for help.
9. My mom cured her kidney stones (by) using stairs and drinking a lot of water.
10. Climbing up stairs is a good way to lose weight.
11. When I was a child, I fell down the stairs and I've had a deep fear of climbing up stairs ever since.
12. Running up and down the stairs is hard for old people.
13. A flight of stairs needs (to be) repaired/fixed.
14. I put my camera at the foot of the stairs for convenience.
15. I climbed to the top of the stairs and shouted like a child.

@Mapleer No grammatical mistakes found in sentences 6 to 15.However, you may consider changing "renal calculi" to "kidney stones" in sentence 9 for clarity.

@Mapleer No grammatical mistakes found in sentences 6 to 15.However, you may consider changing "renal calculi" to "kidney stones" in sentence 9 for clarity.

@Mapleer
No grammatical mistakes found in sentences 6 to 15.
However, you may consider changing "renal calculi" to "kidney stones" in sentence 9 for clarity.

@Mapleer
No grammatical mistakes found in sentences 6 to 15.
However, you may consider changing "renal calculi" to "kidney stones" in sentence 9 for clarity.