Does -ing and un- have grammatical meaning?

Yes, both "-ing" and "un-" have grammatical meaning. Here's how:

-ing

* Present participle: Forms the present participle of a verb, used in:

* Continuous tenses: "She is *singing*."

* Gerunds: "I enjoy *swimming*."

* Adjectives: "The *running* water."

* Noun: Can function as a noun, often referring to an action or process: "The *singing* was beautiful."

un-

* Prefix: Indicates the opposite or negation of the word it's attached to:

* Adjectives: *happy* vs. *unhappy*

* Verbs: *lock* vs. *unlock*

* Nouns: *certainty* vs. *uncertainty*

Key Takeaways:

* "-ing" is a versatile suffix that can function as a verb form, a noun, or an adjective.

* "un-" is a prefix that typically reverses the meaning of the word it precedes.