In English, when we want to show different degrees of comparison for adjectives, we use the comparative and superlative forms. Here's how we complete the table for the given adjectives:
narrow
Comparative: narrower
Superlative: the narrowest
deep
Comparative: deeper
Superlative: the deepest
hot
Comparative: hotter
Superlative: the hottest
expensive
Comparative: more expensive
Superlative: the most expensive
durable
Comparative: more durable
Superlative: the most durable
quiet
Comparative: quieter
Superlative: the quietest
cheap
Comparative: cheaper
Superlative: the cheapest
popular
Comparative: more popular
Superlative: the most popular
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The comparative and superlative forms for the adjectives are: narrow - narrower, the narrowest; deep - deeper, the deepest; hot - hotter, the hottest; durable - more durable, the most durable; quiet - quieter, the quietest; cheap - cheaper, the cheapest; popular - more popular, the most popular.
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