"لكن" is an Arabic conjunction that translates to "but" in English. It is used to introduce a contrast or exception in a sentence. For example, in the sentence "أحب القهوة، لكنني لا أشربها في الليل" (I love coffee, but I don't drink it at night), "لكن" highlights the difference between the speaker's love for coffee and their drinking habits. In Arabic grammar, "لكن" can also be used to connect two clauses, emphasizing a shift in thought. It often appears in formal and informal speech, making it a versatile tool for expressing contradictions. Understanding its usage can enhance clarity in communication.