[#DuolingoForumGems originally posted on 2020-10-14 on the Duolingo Hungarian for English speakers forum by peter.kristof.hu ] 

Consonant rules

Hungarian is certainly a phonetic language, yet in some cases, the pronunciation differs from the written form. This case is when adjacent consonants interact and cause a change in articulation and sometimes in spelling. It can occur between a stem and a suffix, the two parts of a compound word or two words in rapid speech. Knowing this is not negligible in terms of spelling and comprehension.

We describe this phenomenon by the so-called consonant rules. One of them the consonant assimilation that is a sound change in which a consonant becomes similar or identical to the adjacent consonant for easy, more convenient pronunciation. It is also possible that the consonants may merge into a different one - this is the diffusion. In summary, the following table shows the different cases:

	Unmarked in writing	Marked in writing
Partial assimilation	aztán [asztán]	-
Full assimilation	ülj [üjj]	néz+j->nézz
Fusion	látja [láttya]	lát+ja->lássa

("tty"denotes a long "ty" sound.)
For more details on assimilation: https://en.wiktionary.org/wiki/Appendix:Hungarian_pronunciation_assimilation#Assimilation_of_sibilants

1. Partial assimilation The encounter of two adjacent consonants results that the second consonant changes some properties of the first one. The change is based on voicedness or the place of articulation. It appears only in pronunciation, not marked in writing.

• If the first consonant is voiced and the second unvoiced, the first becomes unvoiced. The original and altered consonant differ only in voicedness, i.e. the original sound changes to its counterpart according to the list below.

The voiced-unvoiced pairs:
b-p, d-t, dz-c, dzs-cs, g-k, gy-ty, v-f, z-sz, zs-s.

For example,
aztán -> asztán (then)

More examples:

Spelling	Pronunciation	Meaning
rögtön	röktön	immediately
rabszolga	rapszolga	slave
hadsereg	hatsereg	army
hívta	hífta	he/she called
központ	köszpont	center
vodka	votka	vodka

• If the first consonant is unvoiced and the second voiced, the first becomes voiced. The original and altered consonant differ only in voicedness, similar to the previous description. For example,

népdal -> nébdal (folk song)

More examples:

Spelling	Pronunciation	Meaning
bicikli	bicigli	bicycle
mosdó	mozsdó	bathroom
alakzat	alagzat	formation
képzelet	kébzelet	imagination
csúszda	csúzda	slide
afgán	avgán	afghan

• If the first consonant is n and the second is p or b, the first changes to m, as well as if the first consonant is n and the second is gy or ty, the first changes to ny. For example,

azonban -> azomban (however)
rongy -> ronygy (then)

More examales:

Spelling	Pronunciation	Meaning
színpad	szímpad	stage
ponty	ponyty	carp

2. Full assimilation The full assimilation is that one of two consonant is affected by the neighbouring one as a result of which both sounds become identical. Either the first or the second can change, and the alteration may appear in writing. For example,

az+val -> azzal (with that)

More examples:

Origin	Spelling	Pronunciation	Meaning
	ülj	üjj	sit!
	anyja	annya	his/her mother
	utca	ucca	street
	egészség	egésség	health
néz-j	nézz		see!
mos-ja	mossa		he/she wash / wash!

3. Fusion During a fusion, two adjacent consonants interact, so both changes, then a third consonant is uttered. The fusion is most of the time unmarked. For example,

barátság -> baráccság (friendship)

More examples:

Origin	Spelling	Pronunciation	Meaning
	látja	láttya	he/she sees (indicative)
	szabadság	szabaccság	freedom
	kertjük	kerttyük	their garden
	látszik	láccik	it seems
lát-ja	lássa		see! (imperative)

Finally, here are two more rules.

4. Consonant shortening If a long consonant is placed next to a short one, the long one is shortened.

Spelling	Pronunciation	Meaning
tollbamondás	tolbamondás	dictation
jobbra	jobra	to the right
otthon	othon	home

5. Consonant elision One of the three adjacent consonants, usually the middle one, is not pronounced.

Spelling	Pronunciation	Meaning
rajzszög	rajszög	drawing pin
mondta	monta	he/she told

Tip: Copy and paste the appropriate word into iSpeech:

iSpeech, or use other TTS, e.g. Google Translate.

If you want to read a material related to the topic in Hungarian, here is a list of technical terms:
consonant rules - mássalhangzó törvények
partial assimilation - részleges hasonulás/(asszimiláció)
full assimilation - teljes hasonulás
fusion - összeolvadás
shortening - rövidülés
elision - kiesés
voiced - zöngés
unvoiced/voiceless - zöngétlen
voicedness - zöngésség