correct preposition

I would use "onto".

"Onto" is a directional preposition, while "on" is a locational preposition. See also "Into" and "in". Often they can be used interchangeably. To the extent that these pairs do differ, the compound preposition conveys the completion of an action, while the simple preposition points to the position of the subject as a result of that action. This distinction helps us understand how directional and locational prepositions are related: they stand in the relationship of cause and effect.

See here

http://owl.english.purdue.edu/handouts/esl/eslprep.html

Many thanks, Contrex.

That's American English of course, "onto"

In real English, we would write "on to". But regrettably, we are becoming contaminated little by little.

:wink:

contrex,
According to your link and if I understand correctly, on is also acceptable in Yoong Liat's sentence.

Editing to add this:

"2. Some verbs of motion express the idea that the subject causes itself or some physical object to be situated in a certain place (compare #15-17 above).

Of these verbs, some take only "on". Others take both on and onto, with the latter being preferred by some speakers.

(19) The plane landed on the runway. (not onto the runway)
(20) Sam hung the decoration on the Christmas tree. (not onto the tree)
(21) He placed the package on the table. (not onto the table)
(22) Joanna spilled her Coke on the rug. (not onto the rug)
(23) Samir moved the chair on(to) the deck.
(24) The crane lowered the roof on(to) the house.
(25) The baby threw the pot on(to) the floor."

Isn't sentence #25 similiar to Yoong Liat's?

Yes it is. As your own extract states, the choice of preposition in sentences like example (25) is a matter of preference, and that is precisely why I wrote "I would use 'onto'", and not something excessively prescriptive (and mistaken) such as "'Onto' is the only correct preposition to use in this case".

I intended my use of "I would" to signify that it was a matter of preference.

I accept your (implied?) criticism that my explanation was insufficiently clear regarding the variation of preference among speakers, especially since ESL students often frame questions in such a way that they clearly expect there to be only one "correct" answer.

Seems I need to learn more and more about prepositions.

In my own language, prepositions are not that much.

On, above and over have the same translation, that's "di atas".

In, inside and within have the same translation, that's "di dalam".

Thanks, guys.

I wasn't criticizing you contrex. I only asked that question to make sure I understood the use of those words correctly.

OK! if you had, it would have been fair...