जिन वर्णों का उच्चारण स्वतंत्र रूप से अलग से किया जा सकता है, उन्हें क्या कहा जाता है?

Which of the following words does not change its form based on number (singular/plural) in Punjabi grammar?

Which of the following words is an example of an onomatopoeic word (sound-imitative word)?

Change the following sentence into an interrogative form: 'Suhas reads books.'