Who trained Leonardo da Vinci in inventions?

Answer 1

Nobody. Inventors are often people who can think laterally, or cleverly, and think of ideas that could work. They they work at them to see if they can be the one to succeed. You can't go to school and study inventing.

The one above is an interesting answer. However I would like to add a few things.

Nobody

is not such a correct answer. It is true that inventors are people who think laterally and Da Vinci certainly did. However, it is not true that he was not inspired by certain things and people for his inventions. in 1466 he entered Verrocchio's workshop and that certainly inspired him for his inventions mentally and technically.