The Essential Verb “to Be”
The most notoriously irregular verb in any language is the verb that means “to be.” In some languages, like English, it is actually cobbled together from a few different verbs. In other languages, like Russian, the present tense of the verb “to be” self-destructed and is no longer in use.
The wildly different forms of the English verb “to be” come from three Proto-Indo-European roots. The English present tense (“am,” “is,” and “are”) are from the old root es-. The English infinitive and participles (“be,” “being,” “been”) are from bhu-. The past tense (“was,” “were”) is from wes- meaning “dwell.” Latin doesn't use this root.
Sum
The Latin verb sum is also cobbled together from descendants of the two Proto-Indo-European roots es- and bhu-, even though it doesn't quite look that way. In Latin, the stem for the whole present system is from es-, and the perfect system stem is from bhu-.
Table 12-1 The Verb sum, esse, fuī , futū rus (to be)
The stem for the imperfect and future tenses experienced what linguists call rhotacism. It often happens in Indo-European languages that when an s finds itself sitting between two vowels, that s changes to an r. You can see this in English with the plural of “is” being “are,” and the plural of “was” being “were.” That's why e sam became e ram.
There are a couple more linguistic sleight-of-hand maneuvers that you might find interesting. For the imperfect of sum, cover the er- and replace it with a b-. Look familar? The same thing will happen if you do this with the future. Now cover the fu- in the pluperfect and future perfect and compare them with the imperfect and future. Presto! (Well, except for the -i- in erint.)
The forms for the perfect system don't need any explanation. The endings are regular. It's only the stem that is strange.
The English “be” and the Latin fu- don't look like they have anything to do with each other until you consider the relationship the letters b or p and f have between the languages. It usually happens that where one has a b or a p, the other has an f (e.g., frā ter [“brother”], pater [“father”], ferō [“bear/bring”]).
Possum
Read the following dialog out loud:
“Jeet jet?”
“Naw, jew?”
Here's the same dialog slowed down:
“Did you eat yet?”
“No, did you?”
The Latin verb possum was born from this very same phenomenon. In the case of possum, the slurring is between the adjective potis (“able”) and sum (“to be”).
Table 12-2 The Verb possum, posse, potui-, — — — - (to be able)
The slurring of potis into sum follows some simple rules. There are only three things to remember:
The formula is: pot + a form of sum.
If the form of sum begins with an s, change the t to an s.
If the form of sum begins with an f, drop the f.
The only exception to these rules is the infinitive posse.
Imperfect and future tense forms of possum can be easily confused with forms of the pluperfect and future perfect tenses of possum.
Furthermore, they can all be confused with perfect system forms of pī nī (“to put”). Compare, for example, poteram (“I was able,” “I could”), potueram (“I had been able”), and posueram (“I had put”).
