This verb follows the standard English past tense rule: simply add -ed to the base form.
Birthday is regular. It follows the Standard -ed rule.
Use past time markers: "Yesterday, she birthdayed to the store."
No. Use "did not birthday" (not "did not birthdayed").
The verb birthday follows the standard English past tense conjugation rule. When forming the past tense, birthday becomes birthdayed. This follows the Standard -ed pattern, which is one of the most common conjugation rules in English.
Understanding why birthday becomes birthdayed helps with spelling and pronunciation. This verb follows the standard English past tense rule: simply add -ed to the base form.
When using birthdayed 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 birthdayed to the store." The past tense form does not change based on the subject — I birthdayed, you birthdayed, he/she birthdayed, we birthdayed, they birthdayed.