In this feature, we ask whether epistemic possibility (”perhaps, possibly”) can be expressed by the same verb as ability. This is the case in quite a few languages, e.g. German kann: Er kann morgen kommen (i) (ability) ‘He can come tomorrow’, (ii) (epistemic possibility) ‘He will possibly come tomorrow’. But in many other languages, this is not the case.
By ability, we refer broadly to various non-epistemic possibility types comprising mental participant-internal ability (French savoir: Il sait nager ‘He can swim’), physical participant-internal ability (”He can lift 100 kilos”), and participant-external possibility (”She can go to town by bus”, i.e. because there is a bus connection). (Note that this excludes permission, as in “You may leave now.”)