وليست

In a sentence

• السماء صافية وليست غائمة.

  The sky is clear and not cloudy.

  In this sentence, 'وليست' is used as a negation coordinate conjunction combining two adjective states about the sky.

• هذه الفكرة وليست الأخرى هي المقبولة.

  This idea and not the other is the accepted one.

  Here, 'وليست' helps contrast between two ideas, rejecting one and affirming the acceptance of the other.

• أريد حلاً سليماً وليست عاطفياً.

  I want a reasonable solution and not an emotional one.

  In this case, 'وليست' is employed to express a desire for one type of solution over another, showing preference by exclusion.