I7: How do I detect (+ reject) incomplete multi word verbs?

If I have something like this:

Becoming is an action out of world and applying to one visible thing.

Understand "swap roles with [something]" as becoming.

Inform will treat any mention of “swap” as intending to “swap roles with”, like so:

swap roles with
What do you want to swap roles with?

What do you want to swap roles with?

Is there a nice way to have Inform only recognise “swap roles with” and not “swap” by itself?
I understand that adding a swapping action and writing an understand rule for “swap” will solve the problem, but that gets a bit tedious given that I can “swap”, “exchange”, “switch”, etc. roles with someone.

Sometimes you just do it the tedious way and get on with your game.

However, in this case, you can write the “swap” grammar and then do:

Understand the commands “exchange”, “switch” as “swap”.

This sets up “exchange” and “switch” as synonyms for every “swap” grammar line.