grateful比较级和最高级为什么是moremost含有三个元音及以上的形容词及副词的比较级和最高级才用moremost.请问grateful,helpful为什么也用moremost

Question

grateful 比较级和最高级为什么是more most
含有三个元音及以上的形容词及副词的比较级和最高级才用more most.请问grateful,helpful为什么也用more most

Answer 1

more beautiful; most beautiful
more delicious; most delicious
more ambiguous; most ambiguous
more interesting; most interesting
more important; most imprtant
more easily; most easily
more considerate; most considerate
more respectful; most respectful
more respectable; most respectable
more considerable; most considerable
more cheerful; most cheerful
more pleasant; most pleasant
more grateful; most grateful
more cautious; most cautious
more earnest; most earnest
more serious; most serious
more industrious; most industrious