Form Third Conjugation Verbs in Italian Using -Ire

While there are certainly a lot of regular verbs that conjugate according to the patterns you learn in textbooks, there are also a number of verbs that don’t cooperate with those rules. Third conjugation verbs fall squarely in that category and have a unique feature about their endings that you’ll need to know if you’re going to conjugate verbs like a native speaker.

To start, the infinitives of all regular verbs in Italian end in –are, –ere, or–ire and are referred to as first, second, or third conjugation verbs, respectively.

In English, the infinitive (l'infinito) consists of to + verb.

• amare: to love
• temere: to fear
• sentire: to hear

Start with third conjugation verbs, which are verbs with infinitives ending in -ire. They’re also more simply called -ire verbs.

-Ire Verbs in Italian

The present tense of a regular -ire verb is formed by dropping the infinitive ending (-ire) and adding the appropriate endings to the resulting stem. There is a different ending for each person, “I,” “you,” or “we,” for example.

Capire: To understand (present tense)

Characteristics of Third Conjugation Verbs

When it comes to the indicative and subjunctive present moods, many -ire verbs add the suffix -isc to the first, second, and third person singular and third person plural. The -isc suffix is also added to the second and third person singular and third person plural of the present imperative mood.

Finire: To finish

• io finisco: I finish
• tu finisci: you finish
• egli finisce: he finishes
• essi finiscono: they finish

Present Subjunctive Mood

• che io finisca: that I finish
• che tu finisca: that you finish
• che egli finisca: that he finishes
• che essi finiscano: that they finish
• finisci: you finish
• finisca: he/she/it finishes
• finiscono: they finish

Preferire: To prefer

• io preferisco: I prefer
• tu preferisci: you prefer
• egli preferisce: he prefers
• essi preferiscono: they prefer
• che io preferisca: that I prefer
• che tu preferisca: that you prefer
• che egli preferisca: that he prefers
• che essi preferiscano: that they prefer

Verbs That Use Both Forms

Languire: to languish, to fade

• io languo  
• io languisco

Mentire: to lie

• io mento   
• io mentisco

Other verbs also have both forms but take on diverse significance:

Ripartire

• io riparto: to leave again
• io ripartisco: to divide 

Present Participles Ending in -Ente or -Lente

Generally, the present participle (il participio presente) of third conjugation verbs end in -ente. Several have the form -iente, and a few can have both endings:

• morire/morente: to die
• esordire/esordiente: to begin, to start off, to commence
• dormire/dormente/dormiente: to sleep  

Some participles change the letter that precedes the participle -iente to the letter z:

• sentire/senziente: to feel, to hear

Other popular verbs that are third conjugation and take the -isc suffix are:

• agire: to act, to behave
• approfondire: to increase, to enhance
• capire: to understand
• chiarire: to clarify
• costruire: to construct
• definire: to define
• fallire: to fail
• fornire: to provide
• garantire: to guarantee
• guarire: to heal
• pulire: to clean