[#DuolingoForumGems originally posted on 2020-04-11 on the Duolingo Hungarian for English speakers forum by peter.kristof.hu ] 

Use of plural in Hungarian

I will try to briefly summarize what you need to know about the plural in Hungarian at the morphological and syntactic level.

1. You should know that there are three types of suffixes in Hungarian. An inflected word looks like this:

tő + képző(k) + jel(ek) + rag
in English:
stem + derivational suffix(es) + marker(s) + inflectional suffix

Képző substantially changes the meaning of the word, often even the part of speech.
Jel modifies the meaning of the word slightly but the word still refers to the same concept.
Rag indicates the role of the word in a sentence.
The ending of the plural is a marker ('jel').

2. In Hungarian, the plural marker is -k. Furthermore -i indicates the plural of possession (e.g. könyvei), but I will not discuss it, which could be a separate topic. The suffix k can be taken by nouns, adjectives, pronouns and participles (könyvek, pirosak, valakik, kitűnőek), often by placing a connecting vowel before the marker.

• If the word ends in a consonant, a connecting vowel is placed before the suffix to avoid consonant congestion. Thus, the plural markers have four forms: -ak/-ek/-ok/-ök (házak, könyvek, kabátok, gyümölcsök).

• For some inflected nouns ending in a vowel also inserted a connecting vowel: városiak, újszerűek.

• Words ending in the vowel a or e becomes to á or é, respectively (rózsa -- rózsák, eke -- ekék).

• The stem of some words may change in the plural: étterem -- éttermek, tér -- terek, tó -- tavak, szó -- szavak, kéz -- kezek, ló -- lovak, madár -- madarak, levél -- levelek, tükör -- tükrök, cukor -- cukrok.

3. The appropriate suffix corresponds to the vowel harmony. The following schematic diagram shows the Hungarian vowels:

i              ü             u
    é         ö         o
          e           a
                á

Each of the vowels i, o, ö, u, ü has a long pair: í, ó, ő, ú, ű. Besides, there are two pairs: the short a, the long á and the short e, the long é respectively, but they are different sounds.

We consider 2 types of vowels: front and back. a, á, o, u are back vowels (in bold in the figure), the others are front vowels. i is a particular case. Sometimes it acts as a front, sometimes a back vowel.

Now we distinguish two kinds of words: front and back. Front words have just front vowels in them (kenyér, hideg, felhő, zöld). Back words contain just back, or both back and front vowels (határ, rádió, könyvespolc). Front words take -ek/-ök (könyvek, gyümölcsök) and back words take -ak/-ok (házak, kabátok) ending. I note that further knowledge is needed to discuss this topic. In my opinion, learning this requires a bit of musical hearing and a lot of practice.

4. An attributive adjective before a noun remains in the singular, as in English:
A piros rózsa. --- A piros rózsák. // The red rose. -- The red roses.

5. If the noun is preceded by a numeral, the singular is used:
Két macska, három nővér, sok ember. // Two cats, three sisters, many people.
Also, the singular is used after hány (how many/how much).
Hány nyelvet beszélsz? // How many languages do you speak?

6 Pairs of things are in the singular in Hungarian: Egy pár cipő. Felveszem a cipőmet/nadrágomat/stb.

7. Generally, subjects and verbs must agree with one another in number similar to English. This is also true for the complex predicate where the structure is made up of a nominal and a linking verb ('van'). As we know, often the verb ‘van’ is omitted in the third person.

• The predicate is a verb:
  A kutya üldözi a macskát. -- A kutyák üldözik a macskákat. // The dog chases the cat. -- Dogs chase cats.

• The predicate is a noun (+ the hidden linking verb) :
  A rigó énekesmadár. -- A rigók énekesmadarak. // The thrush is a songbird. -- Thrushes are songbirds.

• The predicate is an adjective (+ the hidden linking verb):
  A rózsa piros -- A rózsák pirosak. // The rose is red -- The roses are red.
  Another example:
  (Én) okos vagyok. -- (Mi) okosak vagyunk. // I am clever. -- We are clever.

• The predicate is a pronoun (+ the hidden linking verb) :
  Ez a kérdés. -- Ezek a kérdések. // This is the question. -- These are the questions.

8. If there are two or more subjects, both the singular and the plural are correct:
Péter és Éva sétál az utcán. -- Péter és Éva sétálnak az utcán. // Péter and Éva are walking down the street.