For nominal conjunction both ek and e are possible, ek seems to be less frequent than e.
For verbal conjunction only e is possible, but in traditional speech juxtaposition is also well attested.
Source: Cellier 1982: 65
Source: Barat et al. 1977: 78
Source: Barat et al. 1977: 15
Source: Barat et al. 1977: 14