Adverb clauses in Thai grammar are groups of words that function as an adverb. That is, they modify a verb, an adjective, or an adverb. They often tell how, when, where, why, under what conditions, or to what degree an action is performed. An adverb clause starts with a subordinating conjunction (e.g., ก็ต่อ, แม้, ถ้า) and includes a subject and a predicate. Understanding how to use adverb clauses properly is important for expressing complex thoughts and relationships between actions or states in Thai.