I am quite confused about the usage over infinitive verbs and gerunds when talking about nouns.
A car for transporting people.
A car to transport people.
both have the same meaning.
The same goes for,
A video for teaching kids geometry.
A video to teach kids geometry.
But why is it that when I say,
A person to talk to.
A person for talking to.
the latter does not match in terms of meaning with the former? The way I'm constructing the sentences hasn't changed compared to the first two examples, yet "a person for taking to" does not have the same meaning as "a person to talk to", while also being quite an awkward expression by itself.
Could anyone explain why this happens?