Latin verbs are divided into 4 conjugations. We can deduct the conjugation from the form of 1st person singular praesens and infinitivus: -o, -are - I conjugation (impero, imperare) -eo, -ere - II conjugation (habeo, habere) -o / -io, -ere - III conjugation (mitto, mittere ; facio, facere) -io, -ire - IV conjugation (venio, venire). The endings of the present tense are the following:

person	singular	plural
1	-o	-mus
2	-s	-tis
3	-t	-nt

Except the 3rd conjugation, these endings are added to the form that we get after removing the infinitive ending -re. In the 1st conjugation, 1st person ends in -o (not -ao): I conjugation:

person	singular	plural
1	impero	imperamus
2	imperas	imperatis
3	imperat	imperant

II conjugation:

person	singular	plural
1	video	videmus
2	vides	videtis
3	videt	vident

In the IV conjugation the 3rd person plur. ends in -iunt :

person	singular	plural
1	venio	venimus
2	venis	venitis
3	venit	veniunt

The III conjugation removes the ending of infinitive -ere. Before the personal ending except -o, we add -i- or (only in 3rd person plural) -u-. Some verbs, like facio, add -i- before the endings -o and -unt. III conjugation, regular verbs:

person	singular	plural
1	mitto	mittimus
2	mittis	mittitis
3	mittit	mittunt

III conjugation, verbs adding -i-:

person	singular	plural
1	facio	facimus
2	facis	facitis
3	facit	faciunt

Outside the conjugation system, there are irregular verbs. The first of them is sum, esse (to be). It's very frequent and very irregular:

person	singular	plural
1	sum	sumus
2	es	estis
3	est	sunt

There are many verbs consisting of prefix + sum (absum, adsum, desum). They conjugate like esse. A very important exception is the verb posse. It has pos- before s and pot- before e.

person	singular	plural
1	possum	possumus
2	potes	potestis
3	potest	possunt

Another exception, similar to possum, posse is: prosum, prodesse (prosum, prodes, prodest, prosumus, prodestis, prosunt).
The verb eo, ire is conjugated like a regular verb of III conjugation, but it has e- before endings -o and -unt.

person	singular	plural
1	eo	imus
2	is	itis
3	it	eunt

Next irregular verb is fero, ferre. It has no vowel before -s and -t.

person	singular	plural
1	fero	ferimus
2	fers	fertis
3	fert	ferunt

Next irregular verbs are volo, velle, nolo, nolle and malo, malle???. The verb volo also has no vowel before -s and -t, and changes o into u in this situation. Irregular forms are also vis and volumus.

person	singular	plural
1	volo	volumus
2	vis	vultis
3	vult	volunt

The verb nolo is conjugated similarly to volo, but when the vowel in volo changes into i or u, the verb is replaced by non + form of volo (vis, vult, vultis).

person	singular	plural
1	nolo	nolumus
2	non vis	non vultis
3	non vult	nolunt

The verb malo is conjugated similarly to nolo : instead of non, ma- is added :

person	singular	plural
1	malo	malumus
2	mavis	mavultis
3	mavult	malunt

Other irregular verbs : fio, fieri, inquam, aio, aiere. Fio is conjugated like a regular verb of the IV conjugation in praesens (fio, fis, fit, fimus, fitis, fiunt). Aio, aiere is conjugated in the same way, but lacks forms in -mus and -tis (aio, ais, ait, aiunt). Inquam has forms like facio, except the 1st person in -m: inquam, inquis, inquit, inquimus, inquitis, inquiunt.