[<< wikibooks] Latin/Lesson 1-Revision
1st declension: genitive ends in -ae, nominative usually ends in -a
2nd declension: genitive ends in -i, nominative usually ends in -us for masculine and -um for neut.
3rd declension: genitive ends in -is, nominative varies
4th declension: genitive ends in -us, nominative usually ends in -us for m/f and -u for neut.
5th declension: genitive ends in -ei, nominative usually ends in -esNotice that almost all 1st declension nouns are feminine.  A mnemonic device for the common masculine ones is PAIN -- poeta (poet), agricola (farmer), incola (inhabitant), and nauta (sailor).  Almost all 2nd declension nouns are either masculine or neuter.
Notice that in all cases, the accusative of neuter nouns is the same as the nominative.

1st Declension

2nd
masculine
-us   -i
-i    -orum
-o    -is
-um   -os
-o    -is
neuter
-um   -a
-i    -orum
-o    -is
-um   -a
-o    -is
3rd
m/f
-?    -es
-is   -um
-i    -ibus
-em   -es
-e    -ibus
neut.
-?    -a
-is   -um
-i    -ibus
-?    -a
-e    -ibus
4th
m/f
-us  -us
-us  -uum
-ui  -ibus
-um  -us
-u   -ibus
neut.
-u   -ua
-us  -uum
-u   -ibus
-u   -ua
-u   -ibus
5th
-es  -es
-ei  -erum
-ei  -ebus
-em  -es
-e   -ebus

A mnemonic device for the common irregular imperatives is the rhyme: dic, duc, fac, fer: there ought to be an "e", but it isn't there. dicite, ducite, facite, ferte.
1st conjugation: amo, amare, amavi, amatus
2nd conjugation: moneo, monere, monui, monitus
3rd conjugation: ago, agere, egi, actus
3rd -io        : capio, capere, cepi, captus
4th conjugation: sentio, sentire, sensi, sensus

Indicative
Active
Present