Biggest and bigger são variações da word big.
O comparative Bigger compara uma person or thing com outra person or thing.
Exemple:
Brazil is bigger than England.
(Veja que Brazil está sendo comparado com a England – ambos são countries).
Já o superlative Biggest compara uma person or thing com um group:
Example:
Brazil is the biggest country in South America.
(Note que, neste example, Brazil está sendo comparado com o group que inclui todos os countries da South America).
Important: Antes do superlative, use sempre ‘the‘.
Quer saber more sobre COMPARATIVE X SUPERLATIVE? Access the originals http://dictionary.cambridge.org/pt/gramatica/gramatica-britanica/comparatives-and-superlatives/comparison-adjectives-bigger-biggest-more-interesting to expand your culture.

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