Obligation & permission (must ~ / may ~)

② Nepali grammar rules

1. Necessity with -नु पर्छ (need to do, with a preceding verb base)

मलाई जानु पर्छ (I need to go) states that I need to go.
With a लाई-marked experiencer, the predicate is पर्छ, not first-person पर्छु.
The spelling -नुपर्छ also occurs.

2. पर्दैन versus हुँदैन

जानु पर्दैन (do not need to go) removes necessity; जानु हुँदैन (must not go) prohibits going.
Affirmative पर्छ expresses obligation/need; permission constructions with हुन्छ express acceptability.
Keep their negatives distinct.

3. Permission patterns

यहाँ बस्न हुन्छ? (it is permissible to sit here) asks permission to sit.
Permission uses patterns with -न हुन्छ (may do, with a preceding verb base) or -नु हुन्छ (may do, a permission pattern); learn prohibition with -नु हुँदैन (must not do, with a preceding verb base).
This differs from one-word respectful present बस्नुहुन्छ.

4. Past necessity

मलाई जानु पर्यो (I had to go) expresses a need that arose/had to be met; जानु पर्दैनथ्यो (did not need to go) past lack of necessity. जानुभएन instead denies that a respectful person went.

5. चाहिन्छ versus पर्छ

मलाई पानी चाहिन्छ (I need water) expresses need for water; मलाई जानु पर्छ (I need to go) need to perform an action. चाहिन्छ commonly takes a needed item/quantity; पर्छ combines with verbal -नु for obligation.
Both can have मलाई as experiencer.

In this obligation pattern, पर्छ does not change for the subject's person.