Third conjugation verbs that take -isc-

If you've been studying Italian any time at all, you know that almost all verbs (with some exceptions like porre, tradurre) end in -are -ere or -ire. They are called the first, second and third conjugations, respectively. But the -ire verbs have a sort of subset that differs from the regular third conjugation pattern. Let's take a look.

Your average, run-of-the-mill -ire verb: sentire.

sento, senti, sente, sentiamo, sentite, sentono.

Your exceptional, wonky, troublesome -isc- verb: finire.

Finisco, finisci, finisce, finiamo, finite, finiscono.

Notice that in the first, second and third singular, and the third plural, a pesky little -isc- inserts itself. In other conjugations, the -isc- disappears, except for the subjunctive and imperative.

While these are the exceptions, they are not rare. And there is no way of knowing besides memorization which are the -isc- ones. Your dictionary or teacher will tell you if they are. Most -ire verbs that start with in- or im- will take the -isc-.

Among the most common verbs in this category are finire (as seen above), capire (to understand, whence the infamous Italian-American capeesh?), agire (to act), colpire (to strike), fallire (to fail), guarire (to heal), impazzire (to go mad) , obbedire/ubbidire (to obey), proibire (to forbid), pulire (to clean), riferire (to refer), stupire (to amaze), tradire (to betray), trasferire (to transfer).

For a complete list, look here.