• Basic forms
• 怪しむ — suspect; doubt / base form
• 怪しみます — suspects; doubts / masu form
• 怪しんだ — suspected; doubted / ta form
• 怪しんで — suspecting … / te form
• 怪しまない — do not suspect / negative
• 怪しめば — if (one) suspects / conditional
• Common expressions
• 行動を怪しむ — suspect someone’s actions
• 態度を怪しむ — doubt someone’s attitude
• More
• 怪しんでいる — is suspecting / state
• 怪しまれる — be suspected
• 怪しまれないように — so as not to be suspected

怪しむ（あやしむ） is a godan transitive verb. It means to suspect or doubt something because it seems strange or unnatural, and is commonly used when judging people’s behavior or situations.