plan on it

[angliholic]

We need to calculate the cost of the trip before we start to plan on it.



Does the above sentence sound right, especially the part in bold? Thanks.

[Naamplao]

We need to calculate the cost of the trip before we start to plan on it.

Does the above sentence sound right, especially the part in bold? Thanks.

No it doesn't. The gerund should be used here

We need to calculate the cost of the trip before we start planning it.

[Anglika]

It can also be phrased "...start to plan it".

[angliholic]

No it doesn't. The gerund should be used here

We need to calculate the cost of the trip before we start planning it.
Thanks, Naamplao, for the reply.
But could you clear it up why "to plan it" doesn't do the trick?

It can also be phrased "...start to plan it".

Thanks, Anglika.