Verbs ending in -e simply add -d to form the past tense. This is the most straightforward regular rule.
Vaccine is regular. It follows the -d Addition rule.
Use past time markers: "Yesterday, she vaccined to the store."
No. Use "did not vaccine" (not "did not vaccined").
The verb vaccine follows the standard English past tense conjugation rule. When forming the past tense, vaccine becomes vaccined. This follows the -d Addition pattern, which is one of the most common conjugation rules in English.
Understanding why vaccine becomes vaccined helps with spelling and pronunciation. Verbs ending in -e simply add -d to form the past tense. This is the most straightforward regular rule.
When using vaccined in writing, remember that it functions as a past tense verb and typically appears with time markers like yesterday, last week, or ago. For example: "Yesterday, she vaccined to the store." The past tense form does not change based on the subject — I vaccined, you vaccined, he/she vaccined, we vaccined, they vaccined.