句子的一致性：指句子結構完整，時態、語態，語氣及句式的一致，舉重個部分共同表達一個獨立、完整的思想。句子各成分之間的.關係應協調，連貫，自然平穩。
下面來看一下句子不統一的幾種情況：
1）句子意思表達不完整
× The lecture was given in such an interersting way.
√ The lecture was given in such an inereresting way that everyone enjoyed it very much.
2）句子的主從關係模糊
× We are going to visit John, and he is our English friend.
√ We are going to visit John who is our English friend.
3) 連接詞使用不當
× The main reason he was absent was because he was ill.
√ The main reason he was absent was that he was ill.
4) 主謂不一致
× Every teacher and student were invited to go to the party.
√ Every teacher and student was invited to go to the party.
5) 中心不明白
× I was watching a film last night, I suddenly found Mary sitting in front of me.
√ When I was watching a film last night, I suddenly found Mary sitting in front of me.
