Two Infinitives in a Row, but Dropping “To”?

Question

Was just thinking about English vs. Spanish and thought about the following sentence: “We can try to run”

In Spanish, I believe this translates as: “Podemos intentar correr”

In Spanish, intentar and correr both have infinitive endings, since they’re following “podemos”.

However, in English, there’s no “to” in front of “try”. Similarly, in sentences like “We will agree to go”, it feels like based on infinitive rules, there should be a “to” in front of “agree”. Meanwhile if you say something like “I need to try to run”, you get the two “to”s.

So I guess the question is, what’s the phenomenon here that makes it so you do or don’t need two “to”s in a row. Is it something special about “can” and “will”? Are there other words that function the same way (maybe like should and could)? Does this have to do with some kind of hidden “conditional” tense in these cases?

Thanks for any info on this!

Answer 1

The majority of verbs with infinitival complements take to-infinitives, like try, plan, and want. However, a number of very commonly-used verbs, like can and will, take bare infinitives (without the to) instead.

Here's the full list of verbs that take bare infinitives, summarized from Huddleston & Pullum (2002) p. 1244 and the preceding section:

• The modal auxiliary verbs can, must, shall, had better, will, may, and would rather, and in certain contexts dare and need. This includes the irregular past-tense forms could, should, would, and might.
• The supportive auxiliary do (as in "He did go to the store today").
• Certain verbs of perception, as in "I saw him leave." These verbs are feel, hear, observe, overhear, see, notice, and watch; all but the last two can occasionally be found with to-infinitives.
• The causative verbs have, let, and make, as in "They made us leave," "They let us leave," and "They had us leave." (Note that this isn't the perfective have.)
• The verb help can be used with either a to-infinitive or a bare infinitive, as in "They helped us (to) get ready."
• The verb know usually takes a to-infinitive, but it can be found with a bare infinitive in British English, as in "I'd never known him lose his temper before."
• The verb ought usually takes a to-infinitive, but it is occasionally used with a bare infinitive in certain contexts in American English (ibid., p. 109), as in "Ought we invite them both?"

Edit: They later add that informal reduced forms like those commonly written as gonna, gotta, wanna, hafta, oughta, supposta, and usta (or useta) are also verbs that take bare infinitival complements, though of course these originated from verbs taking to-infinitives that got compounded with the following to (see pp. 1616-1617).