The past and past participle for "buy" is "bought."
The past indicative and past participle of "buy" are both "bought".
The past tense of buy is bought.
The past participle of buy is bought.
infinitive: buy past: bought past participle: bought
infinitive: buy past: bought past participle: bought
By is not a verb so it doesn't have a past form Buy is a verb. The past of buy is bought
The past participle of the verb to buy is bought.
The past tense of buy is bought.
Buy is present tense. Buying is the present participle. The past and past participle is bought.
The past participle of buy is bought.
Your word simple is throwing me off. Past of buy - bought.