Verbs ending in -e simply add -d to form the past tense. This is the most straightforward regular rule.
Cooperate is regular. It follows the -d Addition rule.
Use past time markers: "Yesterday, she cooperated to the store."
No. Use "did not cooperate" (not "did not cooperated").
The verb cooperate follows the standard English past tense conjugation rule. When forming the past tense, cooperate becomes cooperated. This follows the -d Addition pattern, which is one of the most common conjugation rules in English.
Understanding why cooperate becomes cooperated 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 cooperated 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 cooperated to the store." The past tense form does not change based on the subject — I cooperated, you cooperated, he/she cooperated, we cooperated, they cooperated.