شي

In a sentence

• أريد أن أشتري شيئًا.

  I want to buy something.

  Here, 'شيئًا' is used as 'something', representing an unspecified object, illustrating the indefinite usage of 'شي'.

• هل قد سمعت عن هذا الشيء؟

  Have you heard about this thing?

  Here, 'الشيء' refers to 'the thing', used as a specified known entity, illustrating the definite usage of 'شي' with the definite article 'ال'.

• لا هناك شيء جديد.

  There is nothing new.

  Here, 'شيء' is used in a negation 'لا شيء', translating to 'nothing', illustrating its use in negative constructions.