Conjugate 'sum, esse' (to be) in the present tense.
Conjugate 'sum, esse' (to be) in the imperfect tense.
Conjugate 'sum, esse' (to be) in the future tense.
Why is 'sum' called an irregular verb?
Hint: The stems change (sum / es / est vs. er- in the imperfect and future) rather than using a regular tense sign.
What case does a predicate noun or adjective take after 'sum' (to be)?
Hint: Example: 'Rōma est magna urbs' — urbs is nominative, not accusative.
Translate: 'Rōma est magna urbs.'
Translate: 'Mīlitēs fortēs erant.'
Translate: 'Discipulī bonī erimus.'
What person and number is 'erāmus'?
Compare the future of 'sum' (erō, eris, erit...) with the future of 3rd conjugation verbs (regam, regēs, reget...). What do they share?