In order to play a game of soccer you need ability and a ball, so it's quite natural to say:
(i) I can buy. (ii) I can't buy (Notenote that we are speaking about the ability to buy, no object is required, sentences (i) and (ii) stand on their own feet.) (iii) I can buy food. (iv) I can buy food with money. (v) I can't buy food without money
- I have no money. [to do with what?]
- I have no money with which to buy [to buy what?]
- I have no money with which to buy foodwith which to buy food. [outdated]
- I have no money to buy food with. [the same meaning as 3.]
- I have no money to buy food. [grammatical]
This is quite formal and sometoday's native speakers may find it pompous-sounding and artificial. Nowadays, it is more common to hear:
This construction also holds true in the negative; therefore, after the clause I have no friend we can insert with whom before the verb to play as in sentence #2, or we tagadd the preposition with at the end of the sentence as in #5.
- *I have no pen to write [forto do what?]
- I have no pen to write with
EDIT
In answer to Araucaria's comment “However - I don't understand why to buy food with money is tautological, (i.e. why the ‘with’ is tautological), but to write with a pen is not. In standard British EnglishesEnglish, 4 and 5 are equally acceptable ...”