sentences:  During the sixteenth century this sound evolved into a voiceless velar fricative (, like the "ch" in Scottish "loch"), and "México" began to be pronounced .Given that both "x" and "j" represented the same new sound (), and in lack of a spelling convention, many words that originally had the sound, began to be written with "j" (e.g.it wasn't uncommon to find both "exército" and "ejército" used during the same time period, even though that due to historicity, the correct spelling would have been "exército").