X̄ (X-Bar) The present paper aims to rethink the usefulness of the Universal Grammar (UG) in teaching the English syntax to Thai students. The UG is the shared syntax of all languages, but syntaxes of languages are different because they contain their own parameters. When compared, sentences of two languages can be classified into the same, similar, and different. The same and similar sentence patterns could be said to be the shared UG, while the different ones are the parameters. It is suggested that teachers teach the same and similar sentence patterns before moving to the different ones. Based on theory on language acquisition, it is only after students are competent in the same and similar sentence patterns should they be taught the parameters and more complex sentences. At the same time, teachers should consider errors Thai students make, strategies they use writing in English, and differences between Thai and English that can cause problems in students’ writing and find some possible techniques to solve them, also urging students to use the UG as a monitoring device for writing better sentences.