査 inspect

The tree inspects Abe's hat, to see what it SAW on the night of the assassination (the hat was eventually cleared of all wrongdoing)

checkup ★★★☆☆
検 (investigate) + 査 (inspect) = 検査 (checkup)

Medical checkup. Also, investigation, inspection, review: (fiancial audit, smog check, check the condition of goods that roll off the assemby line, etc). Has the nuance of a test where something passes or fails.

investigate ★★★☆☆
調 (check out) + 査 (inspect) = 調査 (investigate)

an investigation. Emphasizes that there are no correct answers, and implies that the investigators are talking to someone, asking questions directly. (usually used about polls, surveys, and detectives questioning suspects and/or witnesses)

criminal investigation ★★☆☆☆ NP
捜 (search) + 査 (inspect) = 捜査 (criminal investigation)

assess ☆☆☆☆☆
査 (inspect) + 定 (plan) = 査定 (assess)