[#DuolingoForumGems originally posted on 2020-02-29 on the Duolingo Hungarian for English speakers forum by peter.kristof.hu ] 

Direct Object and Conjugation

One of the specificities of the Hungarian language is that verbs require agreement not only with the subject (in person and number) but also with the direct object. The direct object is a verb's argument of a sentence. It is a noun phrase and usually a noun with a suffix -t, optionally with a connecting vowel (asztalt) which indicates the accusative case, but it can be a pronoun (ezt, engem(et)) or an infinitive (olvasni, e.g. tudok olvasni).

Some verbs are only intransitive without definite conjugation (van, jön, megy). They cannot have a direct object argument. There are two kinds of direct objects: the definite and the indefinite.

                             Verb
                       /                \
          Intransitive Verb     Transitive Verb
(cannot have a dir. obj.)     (can have a dir. obj.)
               |                                    /               \
               |                                /                      \         
Indef. Conjug.             Indef. Conjug.           Def. Conjug.
                                The verb has no dir. obj.   The verb has a definite dir. obj.
                                The verb has an indef. dir. obj.

(Source: http://www.nyariegyetem.hu/uploads/Ig%C3%A9k.pdf)

Theoretically, the definite direct object is already a known thing in the discourse.

The definite direct object can be:
- Noun phrase with the definite article: a könyvet, ezt a könyvet, azt a két könyvet
- Possessive form: Péter(nek a) könyvét, Péter(nek egy) könyvét
- Proper name: Pétert
- Demonstrative pronoun: ezt, azt
- Personal, reflexive and reciprocal pronoun: engem(et), magam(at), egymást
- Noun phrase with certain pronouns: bármelyik/valamelyik/mindegyik/összes könyvet (the question word for pronouns: which=melyik)

Otherwise, it is an indefinite direct object.

I don't think a foreign language can be acquired by learning vocabulary and grammatical rules. I believe in intuitive learning methods, however, sometimes the grammatical rules need to be revised.

Definite Direct Object + Definite Conjugation
A könyvet olvasom.
Péter könyvét olvasom.
Péternek a könyvét olvasom.
Péternek egy könyvét olvasom.
Ismerem Jánost.
Ezt a könyvet olvasom.
Ismerem őt.
Ismerem őket.
Az összes könyvet elolvasom.
Bármelyik könyvet elolvasom.
Valamelyik könyvet elolvasom.
Mindegyik könyvet elolvasom.

Indefinite Direct Object + Indefinite Conjugation
The indefinite conjugation is used when the direct object is indefinite or missing.
Olvasok.
Könyvet olvasok.
Egy könyvet olvasok.
Néhány könyvet elolvasok.
Minden könyvet elolvasok.
Kit ismersz?
A fiú, akit ismerek.
Mindenkit/valakit/bármit/valamit ismerek.

Exeptions:
- Látom. - Definite Conjugation. The definite object is thinkable by the context.
- Péter ismer engem(et)/téged(et)/minket/titeket. - Exceptionally in the first and second person of personal pronouns, indefinite conjugation is used.

Source: Új magyar nyelvtan

Verb conjugations with accusative pronouns

[This is taken from the Duolingo Hungarian Tips & Notes ]

Accusative pronouns

You know how to form the accusative (direct object) of a noun. But, pronouns have special forms (like they do in English!).

Person/Number	Nominative	Accusative
1SG	én ‘I’	engem ‘me’
2SG	te ‘you (sg.)’	téged ‘you (sg., obj.)’
3SG	ő ‘he/she’	őt ‘him/her’
1PL	mi ‘we’	minket ‘us’
2PL	ti ‘you (pl.)’	titeket ‘you (pl., obj.)’
3PL	ők ‘they’	őket ‘them’
formal2SG	Ön ‘you’	Önt ‘you’
formal2PL	Önök ‘you’	Önöket ‘you’

When the direct object is a personal pronoun, the situation is a bit more complicated.

Definite conjugation

 [This is taken from the Duolingo Hungarian Tips & Notes ]

The definite conjugation is a bit of Hungarian that we don't have in English.

In sentences with an "accusative " (a direct object), the conjugation depends on whether that object is "definite " or not. The forms we have learned so far are in the indefinite conjugation.

When a direct object is definite, the verb must be in the definite conjugation 

(i) Lát-ok egy kutyá-t.

(ii) Lát-om a kutyá-t.

In (i), the object is indefinite, ’a dog’. In (ii), it is definite, ’THE dog’. In (ii), the verb changes to látom. The ending -om is in the definite conjugation.

(iii) Látom.

Definite and indefinite conjugation

[#DuolingoForumGems originally posted on 2016-08-06 on the Duolingo Hungarian for English speakers forum by jsiehler ] 

Grammar details: Definite and Indefinite

There have been quite a few questions about the use of definite vs. indefinite conjugation. I thought I'd write a little more here in addition to the Tips & Notes that are already provided in case a little more explanation or more examples would be helpful. I've borrowed and adapted from the textbook "Learn Hungarian." This won't be perfect or include every possible detail, but maybe it's helpful anyway.