stand in for (?.)

• act for
• answer for
• appear for
• back up
• change places with
• commission
• crowd out
• cut out
• deputize
• displace
• double for
• fill in for
• front for
• ghost
• ghostwrite
• pinch-hit
• pinch-hit for
• relieve
• replace
• represent
• speak for
• spell
• spell off
• subrogate
• substitute for
• succeed
• supersede
• supplant
• swap places with
• understudy
• understudy for