Multiple choice

This is the most biggest thing I've ever seen (WRONG)

  1. This is the most big thing I've ever seen

  2. This is the more bigger thing I've ever seen

  3. This is the biggest thing I've ever seen

  4. This is the most bigger thing I've ever seen

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The superlative of 'big' is 'biggest'. Using 'most' with 'biggest' is redundant and grammatically incorrect.