A first year teacher friend of mine called last night wanting to know if I knew what an infinitive was. He'd been studying the right answers given in the back, the explanation, the rules, and the examples, but finding it tough going.
So, I said the first simple sentence that popped into my head.
Swimming is fun.
(Gerund [present participle] used as the subject + verb + subject complement)
No problem. He knew gerunds.
I substituted: To swim is fun. (Infinitive serves as subject.)
Sometimes it sounds more natural switched, I inform him.
I like swimming. (Gerund as subject complement)
I like to swim. (Infinitive as subject complement)
We went on to chat for over an hour and a half. At first, as we talked, I kept switching everything into an infinitive form.
He responds, "You've been at this too long," laughing.
So, now I am sleepless. It is the middle of the night. What do I end up thinking about? The pressing swim question.
To swim, or not to swim; that is the question.
Skinny dipping is more fun. (Gerund phrase as subject.)
To skinny dip is more fun. (Infinitive phrase as subject.)
To swim successfully through the stormy seas of life is exhilarating. (Parts of the more complex infinitive phrase = successfully - adv. clarifying how; through the stormy seas - preposition + article + adj. + noun serving as the object of the preposition; etc.)
Here it is 4:30, and I'm still at sea! It's all your fault, you know, friend...
Where's the switch to shut my brain off?