kloie wrote:Can i say sõidan autot kooli?
No, you have to use the comitative case with the vehicle.
In English you could say "I drive a car to school" where "car" is the object of the sentence, but in Estonian the car is not the object so you can't use partitive with it.
Explanation:
Sõitma is a verb that doesn't translate literally to English. Depending on the context it can be translated to English as "to drive, to ride, to travel by" (or even "to go", when going by vehicle). The same verb is even used for riding a horse, travelling by boat, etc. It basically means you are going from one place to another by means of something other than your own two feet.
Grammatically it doesn't take an object so you need to think of it as always meaning "travel by" or "go by means of" (+ comitative case), even when it is translated into English as "to drive".
Sõidan autoga kooli.
I go by car to school which can also be translated as I drive [a car] to school or I ride [a car] to school.
Sõidan bussiga kooli.
I go by bus to school which can also be translated as I ride the bus to school or I take the bus to school.
Sõidan laevaga kooli.
I go by boat to school which can also be translated as I go to school by boat.
Sõidan rattaga kooli.
I go by bike to school which can also be translated as I ride a bike to school.
Sõidan hobusega kooli.
I go by horse to school which can also be translated as I ride a horse to school.
Sõidan kooli.
I go to school. [by vehicle, i.e. not walking] *Don't use this to say that you are a student. Only use it to talk about the action of getting from one place to another. If you want to say "I go to school" in the sense of "I am a student", i.e. "I go to school" in the habitual sense and you aren't emphasizing the method you use to get there, you would say käin koolis.
Now, what if you want to emphasize that you are the driver and you aren't being taken to school by someone else? Often the distinction isn't necessary (or it's assumed that you are the one driving, depending on the context). When the vehicle in question is a car I think I would tend to assume that the speaker was the driver unless the speaker was a child or was someone I knew could not drive themself. But, sometimes my assumption would probably be incorrect and it would turn out there is a group of people in the car and the speaker is in the passenger seat. Maybe it's a group of adults going somewhere together and it's simply not important who the driver is.
Sõidame autoga.
We travel by car.
Then I don't know who the driver is, but in most cases it's not even relevant.
Sõidame autodega.
We travel by cars.
Now maybe we're each driving our own car.
But each car could be full of people and so the speaker might be in a passenger seat.
So you can add more detail when needed:
Sõidan ise autoga kooli.
I drive myself by car to school. (I go myself by car to school.)
Sõidan oma autoga kooli.
I drive my own car to school. (I go by my own car to school.)