1. How to Form Present Participles
Go to the second principal part, and drop the ‘-re’.
Add:
Nom. -ns -ntes (-ntia)
Gen. -ntis -ntium
Dat. -nti -ntibus
Accus. -ntem (-ns) -ntes (-ntia)
Abl. -nti /-nte -ntibus

2. Go to the second principal part, and drop the ‘-ere’ or the ‘-ire’
-io Verb Exception
Go to the second principal part, and drop the ‘-ere’ or the ‘-ire’
Add:
Nom. -iens ientes (-ientia)
Gen. -ientis -ientium
Dat. -ienti ientibus
Accus. -ientem (-iens) -ientes (-ientia)
Abl. -ienti /-iente -ientibus

3. The dog hearing the whistle The whistle heard by the dog
I see the dog.
The dog is seen by me.
The dog hearing the whistle
The whistle heard by the dog
ACTIVE verb
PASSIVE verb
ACTIVE participle
PASSIVE participle
And with an active participle, the noun is the ACTOR / DOER of the participle.
With a passive participle, the noun is ACTED UPON by the participle.

4. How to form the Perf. Pass. Partic.
Go to the 4th Principal Part (which is the Neuter Nom. Sing. PPP)
Drop the ‘-um’ ending and add any 1st/2nd Declension Adjective Ending
(like bonus, bona, bonum)

5. The Perfect Passive Participle (Sing)
laudo, are, avi,
laudatum
Masc
Fem
Neut
Nomin.
laudatus
laudata
Gen.
laudati
laudatae
Dat.
laudato
Accus
laudatam
Abl
laudatā

6. The Perfect Passive Participle (Plur)
laudo, are, avi,
laudatum
Masc
Fem
Neut
Nomin.
laudati
laudatae
laudata
Gen.
laudatorum
laudatarum
Dat.
laudatis
Accus
laudatos
laudatas
Abl

7. Deponent Verbs
There is a category of verbs that are PASSIVE in form but ACTIVE in their meaning. They’re called Deponent Verbs.
As a result a Perfect Passive Participle with one of these verbs has an ACTIVE meaning, and they happen prior to the main verb.

8. Examples of Deponent Participles:
1. ingressus (having entered)
2. regressus (having returned)
3. precatus (having prayed)
4. conspicatus (having caught sight of)
5. locutus (having spoken)
6. adeptus (having obtained)