Grammar and Language Structure (Vyakarana): Sandhi, Samas, Karak, Shabd Roop, Dhatu Roop
Sandhi: joining sounds
The exam asks you to join and, more often, to split and name. Swar sandhi covers dirgha (a+a, i+i, u+u lengthen), gun (a/i/u before a different vowel gives e or o), vriddhi (a with e/ai gives ai; a with o/au gives au), yan (i or u before a vowel becomes y or v) and ayadi. Vyanjan and visarga sandhi appear in a few set words only.
Samas: joining words into one pad
Six types: tatpurush (a case relation is hidden), karmadharaya (adjective + noun, the second member dominates), dvigu (first member is a numeral), dvandva (members joined by "aur"), bahuvrihi (the compound names someone or something else), avyayibhav (first member is an indeclinable). Contrast trilok, where the numeral comes first and the compound means those three worlds (dvigu), with chaturbhuj, which means Vishnu, not "four arms" (bahuvrihi).
Karak and the Magahi postposition
Eight karak - karta, karma, karan, sampradan, apadan, sambandh, adhikaran, sambodhan. Magahi marks most of them with postpositions instead of inflected endings: ke for karma and sampradan, se for karan and apadan, mein for adhikaran. Test the karak with the question word: kaun, ka, ke le, se, mein.
Shabd roop and dhatu roop
Decline nouns for number and attach the right postposition; conjugate roots for person, number and honorific level (tu, tum, aapan). Magahi verbs mark honorificity, but do not carry Hindi's gender agreement into Magahi forms.
Worked example
surya + udaya: a + u gives o, a gun sandhi, so suryodaya, not surya-udaya run together. Reverse-check by splitting the printed word and naming the change; that is exactly how the question is set.
Traps
Mixing sandhi (sound junction) with samas (word compound); labelling every compound tatpurush; ignoring postpositions when naming karak; importing Hindi verb endings into Magahi paradigms.