As you will see the second paragraph is written in the past tense:
Ken was always there for me, you see. I often used to wonder what I’d do without him. He did all the cooking and cleaning. He always made a lovely lemon cake and a grand tuna fish pie. But I did have to keep from running my fingers along the dust on top of the telly. And he pushed me everywhere. Never a word of complaint. And where he couldn’t push me he carried me. It worried me sometimes. It’s selfish, I know, but when you really, really need someone you do worry.
I originally wrote this in the present tense:
Ken has always been there for me, you see. I often wonder what I’d do without him. He does all the cooking and cleaning. He has always made a lovely lemon cake and a grand tuna fish pie. But I do have to keep from running my fingers along the dust on top of the telly. And he pushes me everywhere. Never a word of complaint. And where he can’t push me he carries me. It worries me sometimes. It’s selfish, I know, but when you really, really need someone you do worry.
Then when I got to the end of the story I wanted readers to think that something serious had happened to Ken. So I added something early on to plant this possibility:
It worried me sometimes. It’s selfish, I know, but when you really, really need someone you do worry
I also tried to suggest from the narrator’s reaction that something had gone seriously wrong.
“Ken, Ken, what is it? Are you all right love.”
He rolled over. He was all red in the face.
“Ken,” I said, “Ken, love. What is it?”
He rocked backwards and forwards. His face was wet with tears.
“Dear God, no” I thought. I did. I thought just those words. “Dear God, no.” I felt that helpless.
But I realised that if the second paragraph was in the present tense the reader would know from the start that Ken was going to survive, so I rewrote it in the past tense. I was worried then that I had cheated, and that the tense patterns were not natural. I asked a couple of people to read the text and they made no adverse comment. I then posted it my call page at the Open University. Several people have comments on it. Some have mentioned that they were concerned that Ken might have suffered a disabling or fatal accident. No one suggested that the tenses in the second paragraph were unnatural. I’m still not entirely happy that this is the case. When I rewrite I will add the words Right from the start… at the beginning of the second paragraph. Then I am confident the tenses work all right.
This teaches me two things about the tense system. We make choices in the tense system according to what we want to mean and what effect we want to have on the reader/listener. It’s not just a matter of saying in these circumstance you must use the past tense and in these circumstances you must use the present. The tense system carries far more in the way of meaning than simply indicating time. The second thing is that the time adverbials we choose affect the ‘naturalness’ of tense choices. That’s why I will feel much happier after I have added the words Right from the start ...
What this means for learners, I think, is that we can give them hints and guidelines as to how the tenses are used, but we can’t begin to give a full explanation. If they are to learn how to use the system fully they must learn for themselves from exposure to large quantities of text.