One of the most basic changes that takes place in 関西弁（かんさいべん） is that of the 助動詞（じょどうし） (auxiliary verb) だ. だ is replaced directly byや, with や keeping exactly the same meaning (asserting that something is true).
As や is a replacement for だ, it will follow all of the same conjugation rules. This means that it will mostly be seen after な-Adjectives, or nouns. It should not be attached to verbs or い-Adjectives, unless as part of a set expression.

• あんたの事（こと）が好（す）きや。
  I like you.
• やっぱりあの人（ひと）は綺麗（きれい）や。
  Afterall, that person is beautiful. (Whenever I see that person, I am reminded of their beauty)
• あ、黒猫（くろねこ）や！
  Look, it's a black cat!
• 私（わたし）が好（す）きなパンはこれや。
  This is the bread that I like.

や will regularly be seen in many of the same conjugation patterns as だ, meaning that it conjugates in the same way. A few examples of this are やろ（だろ）, やったら（だったら）, and やけど（だけど）.

• この靴（くつ）可愛（かわい）いやろ。
  Don't you think these shoes are cute?
• 明日（あした）やったら行（い）けるよ。
  If it's tomorrow, I can go.
• 本当（ほんとう）は仕事（しごと）休（やす）みたいんやけど 、人手（ひとで）が足（た）りないから全然（ぜんぜん）休（やす）めない。
  To be honest, I want a day off, but since we are shorthanded, I can't.