Luyện nghe English the American Way: A Fun ESL Guide to Language and Culture in the U.S - Unit 3: Taking a Drive)
To compare three or more things with short adjectives, use the superlative form. Use the and the letters -est.Examples: A midsized car is the fastest.
To compare three or more things with longer adjectives, use the and most.Examples: The luxury car is the most comfortable one of all.
Do not use both most and -est! Do not say the most fastest.