Sentence theory in Estonian grammar focuses on the structure and organization of sentences in the Estonian language. A sentence in Estonian typically consists of a subject, a predicate, and an object. The subject refers to the person or thing that performs the action, while the predicate indicates the action or state of the subject. The object receives the action or is affected by it.

Estonian sentence structure is relatively flexible, allowing for various word orders. The basic word order is subject-verb-object, but it can be changed depending on emphasis or stylistic choices. In addition, word order can be altered to convey certain meanings, such as when using passive voice or emphasizing a specific element of the sentence.

Sentence theory also encompasses other important elements, such as case endings and word order changes related to noun phrases, verb phrases, and adverbial phrases. Additionally, Estonian has specific rules for negation, question formation, and subordination.

Understanding sentence theory is crucial in mastering Estonian grammar, as it provides a foundation for constructing clear and concise sentences. By grasping the rules and patterns of sentence organization, learners can effectively communicate in Estonian and convey their intended meaning accurately.