J-Initial Present Endings

In Hungarian verb conjugation, when a sibilant-final verb stem is followed by a suffix starting with 'j', the 'j' completely assimilates to the preceding consonant, doubling it. (Note that this complete assimilation is specific to verbs; for nouns taking a possessive suffix, sibilant-final nouns usually take the -a/-e variants instead of -ja/-je, so no consonant doubling occurs, e.g., ház + -a = háza).

1. The Affected Consonants:
True Sibilants (-s, -sz, -z, -zs, -dz): These change spelling in both the Definite Present and the Imperative. (Note: You will likely never encounter a verb ending in -zs in practice.)

• -s + j → -ss (e.g., mos + -ja = mossa, mos + -jon = mosson)
• -sz + j → -ssz (e.g., halász + -ja = halássza)
• -z + j → -zz (e.g., néz + -jük = nézzük, néz + -jen = nézzen)
• -dz + j → -ddz (e.g., edz + -jük = eddzük)

Sibilant + t (-st, -szt): These only change spelling in the Imperative/Subjunctive mood (the 't' drops and the sibilant doubles). In the Definite Present, the 't' is retained in both spelling and pronunciation, but it palatalizes (blending with the 'j' to sound like 'ty' or 'cs').

• Imperative: fest + -jen = fessen, választ + -ja = válassza
• Definite Present: festjük, választja (spelled with 't', and pronounced with palatalization, not as a doubled sibilant)

2. Where this happens:
This occurs in two grammatical contexts for sibilant-final stems, but only when the suffix actually begins with 'j':

• Definite Present Tense: Only in forms starting with 'j'. For back-vowel verbs: 3rd sing (-ja), 1st plur (-juk), 2nd plur (-játok), 3rd plur (-ják). For front-vowel verbs: only 1st plur (-jük).
• Imperative/Subjunctive Mood: The imperative marker is '-j', so it affects almost all forms of sibilant-ending verbs.

3. Ambiguity:
Because both the definite present and the definite imperative use the -j marker, the forms often look identical for back-vowel verbs (e.g., Olvassa a könyvet can mean 'He/she reads the book' or 'Let him/her read the book!'). However, for front-vowel verbs, they are only identical in the 1st person plural (e.g., nézzük). In all other forms, the vowels differ (e.g., present nézi vs. imperative nézze). There is no ambiguity in indefinite forms, as the indefinite present does not use a 'j' marker.

4. Other Rules for Sibilant Stems:

• 2nd Person Singular Indefinite: Instead of the usual -sz ending, true sibilant-final verbs take -ol / -el / -öl (e.g., mosol, nézel). Note that -st / -szt verbs do not follow this rule; they take -asz / -esz (e.g., választasz).
• 2nd Person Singular Indefinite Imperative (Short Form): These verbs often use a short form without the final -ál/-él ending (e.g., Olvass! instead of Olvassál!).
• 2nd Person Singular Definite Imperative (Short Form): This specific form drops the 'j' entirely and just adds -d, meaning no assimilation or consonant doubling occurs (e.g., olvasd, mosd, nézd).