1. He spent a lot of money on dancing.

2. He spent a lot of money in dancing.
3. He spent a lot of money on buying things at the shop.
4. He spent a lot of money in buying things at the shop.
5. He spent a lot of money dancing.
6. He spent a lot of money buying things at the shop.

(Which expressions are grammatical?)

1 answer

2 and 4 are incorrect. The others are right.