Verified answer

• hug  - hugged
• mean  - meant
• build  - built
• stand  - stood
• find  - found
• can  - could
• must - had to (когда речь идет об осознанной необходимости, например, "I had to go to school yesterday"), либо must have (когда речь идет о предположении с высокой степенью уверенности, например, "Where is my phone? I must have forgotten it at home".)