1.5 The Verb 'Sum' - Classicalia

Breaking the Pattern

So far, every verb we've met follows a nice, predictable pattern. They all have the same endings: -o, -s, -t, -mus, -tis, -nt. But now we meet the rebel of Latin verbs - sum (to be).

Why is it different? Well, the verb 'to be' is one of the most commonly used verbs in any language. The more a word gets used, the more likely it is to get worn down and changed over time - like a well-worn path that becomes different from the original road.

Think about it: In English, we don't say "I be, you be, he bes" - we say "I am, you are, he is". It's completely irregular! Latin does the same thing.

The Forms of 'Sum'

Here are all six forms of sum in the present tense. Click to reveal each one:

Person	Singular	English	Plural	English
1st	sum	I am	sumus	we are
2nd	es	you are	estis	you (all) are
3rd	est	he/she/it is	sunt	they are

Spotting the Hidden Pattern

Even though sum is irregular, look closely - can you spot some familiar patterns? Let's compare it with the regular endings we know:

Person	Regular Ending	Sum Forms	What's Similar?
1st sing.	-o	sum	Ends in -m (like 'I am')
2nd sing.	-s	es	Has an 's'!
3rd sing.	-t	est	Ends in 't'!
1st plur.	-mus	sumus	Has '-mus'!
2nd plur.	-tis	estis	Has '-tis'!
3rd plur.	-nt	sunt	Has '-nt'!

The secret: Even irregular verbs keep hints of the regular pattern! The endings are hiding inside the words - this makes them easier to remember.

How 'Sum' Works Differently

Here's something special about sum: it doesn't take an accusative object like other verbs. Instead, it links two nominatives together. We call the second nominative the complement because it completes the meaning.

Think of it like an equals sign in maths: subject = complement. Both parts describe the same person or thing, so both stay in the nominative case!

Remember: With regular verbs: nominative (subject) + verb + accusative (object)
With sum: nominative (subject) + sum + nominative (complement)

Examples to Practice

Click each sentence to see the translation. Notice how both nouns are in the nominative:

Simple Statements

servus sum.

puella ancilla est.

domini amici sunt.

ancillae sumus.

Special Usage: 'There is/are'

est deus.

sunt dei.

Tip: When est or sunt come first in a sentence, translate them as "there is" or "there are" rather than "he/she/it is" or "they are".

Practice Activities

Exercise 1.22

Exercise 1.23

The Verb 'Sum'