In the sentence below:
The only way to communicate with me is ________ me directly an email.
should I fill in the blank with sending or to send? Or will both work?
Is there a general rule to determine when should we use verb-ing or to verb?
I think either form would be acceptable, but something else is bothering me about the sentence. I would move the word “directly” to the end of the sentence:
The only way to communicate with me is to send me an email directly.
The only way to communicate with me is sending me an email directly.
Of these cases, I would prefer to hear the first option. It sounds more natural to me.
You can make the second sound more natural by adding “by”:
The only way to communicate with me is by sending me an email directly
Adding “by” has a lot of impact on how I read the sentence, and it suddenly feels very natural. Not sure why, though. I would say that when using this form, always use “by”.
It depends on what you what to say. However in your case 'is to send' is fine. Therefore: "The only way to communicate with me is to send me directly an email." However you can simply say it as: "Email is the only way to communicate with me"