One thing we notice about Lord Capulet's first speech in the ball scene, Act 1, Scene 5, is that most of his lines end with exclamation points. We especially see exclamation points while he is welcoming his guests, such as in the line, "Welcome, gentlemen!" (I.v.15). We even see him using exclamation points in commanding the servants to clear more space so that his guests can dance more comfortably. All of these exclamation points serve to show that Capulet is in a gay, happy mood and excited about entertaining his guests at his ball.
Another thing we can notice is that the language he uses in his first speech portrays him as flirting with his guests, which also shows his gay mood. For example, after encouraging the ladies to dance, he next says:
Ah ha, my mistresses! which of you all
Will now deny to dance? She that makes dainty,
She, I'll swear, hath corns. (17-19)
What he is saying here is that any lady who refuses to dance does so because she has corns on her feet. In other words, he is teasing the ladies in order to encourage all of them to dance. His teasing is also a form of flirtation, and his flirtation shows us just what a gay, happy mood he is in. Diction in these lines also show just how flirtatious Capulet is being. In particular, the word "dainty" can be translated as meaning delicate; therefore, Shakespeare's choice to use the word "dainty" helps portray the ironic image Capulet is describing in these lines, specifically, the image that if women act daintily and delicately by refusing to become physical and active through dancing, he will tease them by saying that they have corns on their feet. Therefore, the diction choice of the word "dainty" perfectly illustrates Capulet's teasing, flirtatious nature in these lines, due to his joy over giving a ball.