"Put finger on" is an idiomatic expression that means to identify or point out something with certainty. However, there are numerous synonyms to use in place of this expression, such as pinpoint, identify, isolate, recognize, distinguish, and diagnose. The word pinpoint means to identify the exact location or cause of a problem. Identify means to recognize or diagnose a particular person or thing. Isolate means to separate or distinguish something from a group or context. Recognize means to acknowledge or identify something or someone as known or previously encountered. And, distinguish means to set apart or differentiate from others. These synonyms can add variety and nuance to the language while conveying a similar message.