Hello native English speakers. Sorry to disturb you. Thank you in advance very much. Queries about the tense for real seven sentences. 1a. I have always lived there. 1b. I always lived there. 1c. I used to live there. Question: Which is grammatically correct? Do they have the same meaning? 2a. I have been in his office several occasions. 2b. I was in his office several occasions. The same question as above. 3a. Every time I have seen them, they have been swimming. 3b. Every time I saw them, they was swimming. The same question as above. 4a. Whenever I have tired carpentry, I have cut my finger. 4b. Whenever I tired carpentry, I cut my finger. 4c. Every time I tired carpentry, I cut my finger. The same question as above. 5a. After I have seen her, I feel encouraged. 5b. After I saw her, I felt encouraged. The same question as above. 6a. I don't go to bed until I have finished my work. 6b. I don't go to bed until I finished my work. 6c. I didn't go to bed until I finished my work. The same question as above. 7a. When I have asked a London policeman the way, I have invariably received a polite answer. 7b. When I always asked a London policeman the way, I often invariably received a polite answer. 7c. When I asked a London policeman the way, I invariably received a polite answer. 7d. Whenever I asked a London policeman the way, I invariably received a polite answer. The same question as above.