Date: 201705
Local time of day: 1201-1800
Location: CZYZ.ARTCC, ON
Flight conditions: VMC
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
ATC / advisory: Center CZYZ
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Captain; Pilot Flying
Anomaly: Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Contributing factors: Human Factors; Procedure
Primary problem: Procedure

Narrative: While on Initial arrival segment in descent talking with Toronto Center I was the Pilot not Flying (NFP); airspace became clogged. Center began issuing us vectors 'to spin us once around' before sending us in. During these vectors we were cleared to descend to 13;000'. We were given what I felt was an ambiguous clearance; and I directly queried the English as a Primary Language controller. 'You want us to turn direct to next arrival fix descend now to 12;000; and then cleared to descend via the star?' He stated affirmative. Approaching the fix he turned us over to Toronto Approach. We passed the 12;000 fix and began a descent. At an Altitude of less than 11;500'; Toronto Approach recleared us to descend to a lower altitude and asked if we had left 12;000. I stated we had and the controller stated in Canada; all descend Via Altitude's are given by controller. I asked if he would file any paperwork and his response was yes; they have had hundreds of violations in the past week due to a recent ICAO phraseology change.When we asked if we were cleared to descend via the star; the controller replied 'affirmative'.Even though we briefed it; due to off airway vector; and then ambiguous clearance while off airway; we queried the controller with more concise and direct language. Our interpretation of descend via is different than Canadian interpretation; due to a recent ICAO language change; in 2 countries whose primary language is English.[Manufacturers] training pilots that upon hearing the words 'descend via'; a pilot should set the lowest publish altitude in the altitude window for a managed profile descent. This was also a contributing factor to the language interpretation and phraseology misinterpretation.Both pilots were on day 1 of a new base and [a] new route that neither had flown.Critical Flight information to be appended to [Company] message; so that future crews understand descend via only means 'meet the speeds'; not the altitudes. Only descent to an arrival altitude when cleared to a specific altitude. Republish in [Company] messages for all crews. Add ICAO language phraseology changes to distance learning with a question to test for understanding. Languages instituted less than 8 days prior; and controller stating 'hundreds' was very disconcerting.Require a Verbal Prebriefing with the dispatcher 'noted on release' to review this language and this provide additional guidance and reinforcement about the verbal language trap and what not to do.


Second narrative: [Report narrative contained no additional information.]


Synopsis: Flight crew reported an altitude deviation on a STAR into CYYZ and were informed in Canada a 'descend via' clearance only means speeds not the altitudes.