Subject with multiple verbs
I wrote this sentence:
In both cases, execution is asynchronous, and results in the execution of the command or event handler on the program’s one thread at the next opportunity.
I was told that I need to change it to "and it results", because the lack of subject makes the sentence hard to understand. I thought it should be obvious that the subject of "results" is the first "execution", but is that correct?
I should probably replace the first "execution" with "invocation" to avoid the repetition, but do I need an "it" before "results"?
Solution 1:
Your sentence is grammatical as it stands, and having a single subject with two conjoined verb phrases is common in all forms of writing and understandable in general.
However, the problem with easily parsing your particular sentence stems from the fact that results can be both a 3rd person singular form of a verb (as you intend) or the plural form of the noun result. Because of the way the sentence is constructed, both interpretations of results are possible until you reach the end of the sentence and see that noun-results would have no verb in its clause. At this point, the reader must go back and try to parse the sentence differently.
Using it in front of results is not a grammatical requirement, but it eliminates this ambiguity. Other similar ways to avoid this ambiguity include:
- "In both cases, execution is asynchronous, which results in the execution..."
- "In both cases, execution is asynchronous, resulting in the execution..."
Solution 2:
No. You do not need the "it". It would, however, help your sentence not to repeat the "execution".
And "it" might be helpful if you are talking to an audience who cannot comprehend English well.
There are sentences which do need an equivalent "it", because there are too many words in between the subject and the second verb, but this is not the case in your sentence.
You have to realize that since grammar is not in question, all of the above is my opinion, based on everything I've read and heard.