I have a grammar-related question about the following examples
I just don't know which one is correct from a grammar standpoint and honestly, I've heard Americans saying it the three ways, Is there a rule I can apply in general or would you say It depends entirely on the verb following the linking verb IS?
Example 1
The government created a special bureau whose only responsibility is to monitor the elections.
The government created a special bureau whose only responsibility is monitor the elections.
The government created a special bureau whose only responsibility is monitoring the elections.
Example 2
All you have to do is run.
All you have to do is to run.
All you have to do is running.
Example 3
To Darlene, the most important thing is win the race.
To Darlene, the most important thing is to winthe race.
To Darlene, the most important thing is winning the race.
Example 4
Byron’s idea was go to the fitness club.
Byron’s idea was to go to the fitness club.
Byron’s idea was going to the fitness club.
I think the rules are more consistent than they first appear. Here are my comments:
The government created a special bureau whose only responsibility is to monitor the elections. GOOD
The government created a special bureau whose only responsibility is monitor the elections. BAD
The government created a special bureau whose only responsibility is monitoring the elections. GOOD
We can reasonably think of this responsibility as both an idea or concept (infinitive "to monitor") or an activity (gerund "monitoring")
All you have to do is run. GOOD
All you have to do is to run. GOOD
All you have to do is running. BAD
We have a "to" here already in "have to". For that reason (I think), the "to" before "run" is optional ("You have to run").
"To run" is OK for the same reason as "to monitor" (above). So I think that two different grammar rules can apply here. I am not 100% sure.
The third one sounds bad, perhaps because you can't say "I have to running".
To Darlene, the most important thing is win the race. BAD
To Darlene, the most important thing is to win the race. GOOD
To Darlene, the most important thing is winning the race. GOOD
Same analysis as for "monitor".
Byron’s idea was go to the fitness club. BAD
Byron’s idea was to go to the fitness club. GOOD
Byron’s idea was going to the fitness club. GOOD
Same analysis as for "monitor" and "win."
I'm a native speaker, definitely not a grammar expert though. However, I can tell you that in all of your examples "to _________" and "________ing" are equivalent, so one does not sound wrong if the other sounds right. It also definitely does not depend on the verb following is, and I can show you what I mean better by using the same word in your examples:
Example 1:
His only responsibility is to run.
His only responsibility is running.
His only responsibility is run.
Example 2:
All he has to do is to run.
All he has to do is running.
All he has to do is run.
Example 3:
The most important thing is to run.
The most important thing is running.
The most important thing is run.
...The highlighted sentences are correct, at least in that they sound familiar as a native speaker. Notice that in each case, if "to run" sounds correct, then "running" sounds correct. It would seem to me that these are interchangeable, but I could be wrong. As far as when to leave off the "to," I'm not sure how much I can help there, other than to say that it seems that when the subject is "he" you will use run, but if not you use "to run" or "running." This applies for every regular verb I can think of. Again, I could be wrong, but this is what sounds right. Hope it helps some!
