Глагол know в английском языке употребляется в разных временах, например:

• Simple Tense (простое, неопределённое время): 1
• Present Simple — простое настоящее: I know, you know, he, she knows, we know, you know, they know. 13
• Past Simple — простое прошедшее: I knew, you knew, he, she knew, we knew, you knew, they knew. 13
• Future Simple — простое будущее: I will know, you will know, he, she will know, we will know, you will know, they will know. 13
• Continuous Tense (длительное время): 1
• Present Simple Continuous — настоящее длительное: I am knowing, you are knowing, he, she is knowing, we are knowing, you are knowing, they are knowing. 13
• Past Simple Continuous — прошедшее длительное: I was knowing, you were knowing, he, she was knowing, we were knowing, you were knowing, they were knowing. 13
• Future Simple Continuous — будущее длительное: I will be knowing, you will be knowing, he, she will be knowing, we will be knowing, you will be knowing, they will be knowing. 13
• Perfect Tense (совершенное время): 1
• Present Perfect — настоящее совершенное: I have known, you have known, he, she has known, we have known, you have known, they have known. 13
• Past Perfect — прошедшее совершенное: I had known, you had known, he, she had known, we had known, you had known, they had known. 13
• Future Perfect — будущее совершенное: I will have known, you will have known, he, she will have known, we will have known, you will have known, they will have known. 13
• Perfect Continuous Tense (длительное совершенное время): 1
• Present Perfect Continuous — настоящее совершенное длительное: I have been knowing, you have been knowing, he, she has been knowing, we have been knowing, you have been knowing, they have been knowing. 13
• Past Perfect Continuous — прошедшее совершенное длительное: I had been knowing, you had been knowing, he, she had been knowing, we had been knowing, you had been knowing, they had been knowing. 13
• Future Perfect Continuous — будущее совершенное длительное: I will have been knowing, you will have been knowing, he, she will have been knowing, we will have been knowing, you will have been knowing, they will have been knowing. 13