Date: 201812
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: Regional Jet 900 (CRJ900)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Landing
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ; Tower ZZZ
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Human factors: Communication Breakdown; Situational Awareness
Second reporter function: Pilot Flying; Captain
Anomaly: ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Detector: Person Flight Crew
When detected: Other Landing
Result: Air Traffic Control Provided Assistance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: Coming in to land expecting [Runway] XXR into ZZZ. Had current ATIS and noticed XXs were landing; we set up for [Runway] XXR. All ops were normal. We were cleared for the visual and read back for [Runway] XXR; we expected an aircraft we were following to land for [Runway] XXL. That aircraft lined up for for [Runway] XXR instead; and when we switched to Tower; we emphasized for [Runway] XXR and were nearly lined up with it. They cleared us to land for [Runway] XXL; we queried them and they said and emphasized for [Runway] XXL. They said the other aircraft was for [Runway] XXR and we should be for [Runway] XXL; so we switched to the other runway. Both Tower and us emphasized for [Runway] XXL; we both agreed on it; and we switched the frequency for an otherwise uneventful visual for [Runway] XXL landing.Apparently ATC and we had different ideas on who was doing what. We understood that the prior aircraft was landing for [Runway] XXL and we were landing for [Runway] XXR and read back for [Runway] XXR as far as I remember. It was clear there was an error somewhere so we verified and corrected it with Tower.Without hearing the recordings of the conversations from Approach; Tower; and us; I don't have a suggestion. It may have been simply an expectation bias on our part or maybe a simple mistake somewhere. I felt like we handled it fine and adjusted because we saw the aircraft ahead and it didn't look right.


Second narrative: While on approach into ZZZ; ATC told us to expect [Runway] XXR; Approach cleared us for the visual XXR (that's what Pilot Monitoring read back). When passed over to Tower Controller; they cleared us to land on the other runway; [Runway] XXL. We asked Tower to verify a runway change; he confirmed and told us we were supposed to be on the left side for the visual; as there was a heavy jet on the right side. He asked whether we could accept a runway change; and; since it was a longer runway and we were outside the final approach fix; we accepted. We switched localizer frequencies and were well within stabilized approach criteria. Landed without incident. We are not sure the cause. On debrief; the First Officer and I both agreed that we had responded with [Runway] XXR on all clearances. We both remember getting cleared for the right side. Whether that was expectation biased or not; we definitely responded on the radio with the [Runway] XXR clearances and were not corrected by ATC. Tower asked us; when we landed; to clarify that we had been set up for the right side and that he was asking Approach why they had cleared us for that side .


Synopsis: CRJ-900 flight crew reported communication breakdown between flight crew and ATC regarding landing runway.