It surprises me to see that in some aircraft inventory listings, a rather considerable percentage of combat aircraft are "trainer" versions.
For Spain, it is claimed they have 56 Eurofighter 2000, and 12 trainers. Somewhat similar numbers apply to their F-18 variants regarding combat aircraft and trainer aircraft.
I'm curious what the difference is between these Eurofighter 2000 combat vs. trainer aircraft. In particular, how much effort is it to make a trainer EF2000 combat ready? Perhaps they actually are combat ready? Surely there are some differences though, such as having two seats? What else?