In order to study and remember the different conjugations of the Praesens Activum well, it is important to take a close look to the differences between the five conjugations.

SECOND CONJUGATION

The basic vowel in the second conjugation is e, the endings are -o, -s, -t, -mus, -tis and -nt (-re for the infinitive). Be careful: in the first singular form the basic vowel doesn't disappear following the presence of the ending o, which does happen in the first conjugation. The example verb is monere (=to advise, to warn), the stem of that verb is mon.

Verbum monere - verb to advise, to warn (stem = mon)
moneo - I advise
mones - you (s.) advise
monet - he/she/it advises
monemus - we advise
monetis - you (pl.) advise
monent - they advise

Some other verbs of the second conjugation:
habere - habeo - to have
iubere - iubeo - to order, to command
tenere - teneo - to hold
videre - video - to see
frigere - frigeo - to have cold