Is there a sentence without an adjective or adverb phrase?

Yes, there are many sentences without adjective or adverb phrases. Here are a few examples:

* "The cat sat on the mat." This sentence only contains nouns, verbs, and prepositions.

* "She walks." This sentence has a subject and verb, but no modifiers.

* "I went to the store." Again, just a subject, verb, and prepositional phrase.

To be more specific, a sentence can exist with only a noun phrase and a verb phrase. Adjective and adverb phrases are optional elements that add detail and description to the sentence.