• Basic forms
• 指す — to point; to indicate; to designate / base form
• 指します — (I) point; indicate / masu form
• 指した — pointed; indicated / ta form
• 指して — point and …; indicate and … / te-form
• 指さない — do not point / negative form
• 指せば — if (you) point / conditional
• 指せ — point! indicate! / imperative
• Other common forms
• 方向を指したい — want to point the direction / 〜たい form
• 道を指せる — can point the way / potential
• 指せた — was able to point / past potential
• 指せない — cannot point / negative potential
• More
• 指そう — let’s point; let’s indicate / 〜よう form
• 指さなかった — did not point / past negative
• 指している — is pointing; is indicating / progressive

指す（さす） is a godan verb ending in す. Stem alternates as 指し → 指す → 指して → 指した. Used for physically pointing, indicating directions, or designating something such as a position or concept.