Below is a list where you can find all 26 Al Bhed Primers, by collecting these you can learn to speak and understand the Al Bhed language.

Al Bhed Primers
Location
Vol. I
Al Bhed Salvage Ship
Vol. II
Besaid Village-Crusaders Lodge
Vol. III
S.S. Liki-Engine Room
Vol. IV
Kilika--Tavern
Vol. V
S.S. Winno-Bridge
Vol. VI
Luca Stadium-Basement B
Vol. VII
Luca Theater-Reception
Vol. VIII
Mi'ihen Highroad-From Rin
Vol. IX
Mi'ihen Highroad-Newroad, North
Vol. X
Mushroom Rock Road-Precipice
Vol. XI
Djose Highroad
Vol. XII
Moonflow-North Wharf
Vol. XIII
Guadosalam-House
Vol. XIV
Thunder Plains-Agency or Sanubia Desert
Vol. XV
Macalania Woods-Lake road
Vol. XVI
Lake Macalania-Agency Front
Vol. XVII
Sanubia Desert-Central
Vol. XVIII
Sanubia Desert-Central
Vol. XIX
Al Bhed Home
Vol. XX
Al Bhed Home-Living Quarters
Vol. XXI
Al Bhed Home-Main Corridor
Vol. XXII
Bevelle Temple-Priests' Passage
Vol. XXIII
The Calm Lands-Central
Vol. XXIV
Remiem Temple
Vol. XXV
The Calm Lands-Cavern of Stolen Fayth
Vol. XXVI
Omega Ruins

Once you have collected all 26 Al Bhed Primers then Rin will present you with 99 Underdog's Secrets in the Airship corridor.