Don't Shift Your Tenses (it makes me nervous)

Shifting tenses is a common mistake writers make, especially when in narratives. Look at the following example:

The air is dripping with expectation. We all knew that something was going to happen as we took our places around the dinner table. Each of us was sure that Dad was going to come down on us for something, even though we had all worked so hard to bring up our grades over the last few months.

We are all nervous, but we hope it doesn't show. Dinner is usually a fun time, where we get to share the events of the day,while we eat the fine meal Mom has prepared.

I'm twelve years old now and this is the first time I've seen Dad really angry. The look on his face is enough to scare the worst demon in hell.

Finally, I asked him "What was your day like, Dad?"

But Dad says nothing; he just scowls at me and then slowly turns to scowl at my brothers and sisters.

Notice how the writer shifts back and forth between tenses. He begins in the present: "The air IS dripping," then immediately shifts to the past. "We all KNEW..." If the story begins in the present tense, it should stay in the present tense. If it begins in the past tense, it should stay in the past tense. "The air is dripping..." should be followed with "We all KNOW..." or should be changed to "The air WAS dripping..."

The pattern of shifting tenses continues in the second paragraph with a shift back to the present: "We ARE all nervous..." and another shift, back to the past in the next sentence: Dinner IS usually a fun time..."

The third paragraph stays in the present tense, but the fourth paragraph takes another abrupt shift with: "Finally, I ASKED him..." which ought to be "I ASK him..." if the writer wants to stay with the present tense, which is where he goes with the last paragraph, shifting back to the present with: "But Dad SAYS nothing..."

Here's a revised version of the piece with the verbs changed so that it's entirely in the past tense:

The air was dripping with expectation. We all knew that something was going to happen as we took our places around the dinner table. Each of us was sure that Dad was going to come down on us for something, even though we had all worked so hard to bring up our grades over the last few months.

We were all nervous, but we hoped it didn't show. Dinner was usually a fun time, where we got to share the events of the day, while we ate the fine meal Mom prepared.

I was twelve years old and that was the first time I saw Dad really angry. The look on his face was enough to scare the worst demon in hell.

Finally, I asked him "What was your day like, Dad?"

But Dad said nothing; he just scowled at me and then slowly turned to scowl at my brothers and sisters.

And here's another version, this time using the present tense:

The air is dripping with expectation. We all know that something is going to happen as we take our places around the dinner table. Each of us is sure that Dad is going to come down on us for something, even though we have all worked so hard to bring up our grades over the last few months.

We are all nervous, but we hope it doesn't show. Dinner is usually a fun time, where we get to share the events of the day,while we eat the fine meal Mom has prepared.

I'm twelve years old now and this is the first time I've seen Dad really angry. The look on his face is enough to scare the worst demon in hell.

Finally, I ask him "What was your day like, Dad?"

But Dad says nothing; he just scowls at me and then slowly turns to scowl at my brothers and sisters.

Either of these versions (past or present) is acceptable, but when you confuse the tenses by shifting back and forth you confuse your reader. The reader can't tell if you're talking about something that is happening NOW or something that happened some time in the past. Be sure you're clear about that. Such tense shifting jars the sensibilities...and it makes ME nervous.