The purpose of this research is to discover problems in the logical consistency of school grammar terms, focused on clauses and phrases, for desirable solutions. Embedded sentence must be renamed as “embedding clause” because they are not a complete sentence; rather, it is included in the whole sentence. Including the embedding clause to a complex sentence must be called as “including sentence.” Conjunctive sentences generally have front clause and back clause. As the logic follows, coordinate sentences also have a front coordinate clause and back coordinate clause. However, the front and back clauses are not appropriate terms to describe sentences that are connected within the subordinate or including sentence. Combining the terms, subordinate clause and main clause, and embedding clause and including clause have the logical consistency. The characteristics of clauses show units such as subject and predicate while those of phrase do not. Phrases are formed by having two or more words and plays a consistent grammatical unit. Therefore, they are not restricted to be used as a component with a group of words such as noun phrase or verb phrase, or as a component of sentences such as descriptive phrases. Such solutions guarantee the logical consistency of school grammar terms.