The purpose of this study is twofold: (i) to examine the extent to which English native speakers' abide by the grammar rule of concord that the verb must agree with its subject in number, and (ii) to highlight the implications of the obtained results for EFL teaching/learning process. For this purpose, a test consisting of 23 concord items was devised and presented orally and in writing to two different groups of English native speakers. The results showed that the majority of native speakers do not actually follow the formal rule of concord and resort to other kinds of concord under the pressure of semantic content. These findings have pedagogical implications for EFL teaching/learning process. EFL teachers, when teaching grammar, should take into consideration not only what traditional grammars say but also what native speakers actually say.