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