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