Verbs ending in a consonant followed by -y change the -y to -ied in the past tense form.
Billy is regular. It follows the -ied Conversion rule.
Use past time markers: "Yesterday, she billied to the store."
No. Use "did not billy" (not "did not billied").
The verb billy follows the standard English past tense conjugation rule. When forming the past tense, billy becomes billied. This follows the -ied Conversion pattern, which is one of the most common conjugation rules in English.
Understanding why billy becomes billied helps with spelling and pronunciation. Verbs ending in a consonant followed by -y change the -y to -ied in the past tense form.
When using billied 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 billied to the store." The past tense form does not change based on the subject — I billied, you billied, he/she billied, we billied, they billied.