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