Question:In an attempt to produce premium oysters

[tim]

I would prefer to write this one as "I've switched off my laptop by pressing the shut down button". Yours doesn't seem right, and as I reflect on it further* I think it's because your sentence feels like the cause and effect are backwards. In my sentence, I've made it clear that pressing the shut down button is what switched off the laptop. Your example makes it sound like switching off the laptop caused the shut down button to be pressed.

*See what I did there? I said something doesn't sound right, but instead of just dismissing the sentence right there I explored WHY it doesn't sound right. As I'm sure you're all well aware, "sounds wrong" should never be used as a reason on its own for eliminating a SC answer, but for those of you who have a good spidey sense about the English language it can often help you identify where to focus your attention and your application of grammar rules. Think of it this way: if you hear a rustle in the bushes, that's no guarantee there's a bad guy lurking there, but if you're looking for a bad guy, that rustle in the bushes you just heard seems like as good a place as any to start your search.

[RonPurewal]

if you want to preserve the 'comma + __ing' structure, you CAN write the sentence in the reverse order:
I pressed the button, shutting down the computer.

this statement presents, as accurately as possible, both
... what you actually did directly (= pressing the button)
... the immediate consequence of that action (= shutting down the computer).

[RonPurewal]

if the difference still isn't clear (or if it's not clear to you why the difference is important), consider the following pair of sentences:

After the surgery Lawrence regained his physical strength, gaining back twenty pounds of lean body mass..

After the surgery Lawrence gained back twenty pounds of lean body mass, regaining his physical strength..

make sure you understand the difference.
the difference is explained in the next post. before you scroll down, try to explain the difference by yourself.

[RonPurewal]

After the surgery Lawrence regained his physical strength, gaining back twenty pounds of lean body mass..

this sentence ^^ suggests that lawrence worked directly on his strength (by lifting weights, or through physical therapy, or whatever), and that the weight gain happened as a consequence.

After the surgery Lawrence gained back twenty pounds of lean body mass, regaining his physical strength..

this sentence ^^ suggests that lawrence did NOT work directly on his strength. rather, he regained his physical strength as a result of regaining the weight that he had lost.