deep的比较级是deeper；最高级是deepest。
deep作为形容词时，意思是：深的；宽的；有…深的；深呼吸的；靠近对方端线的；极度的；严重的；酣睡的；专注于；强烈的；衷心的；难懂的；低沉的；城府深的；渊博的。
deep作为副词时，意思是：深深地；深入地；本质上；在内心深处；深陷(债务等中)。
deeper造句示例：
1、A few minutes later, the pressured strokes started to produce a relieving effect and my body and mind began to sink deeper into relaxation.
几分钟后，这种有力的按压开始产生一种让人放松的效果，我的身心都开始深深地沉漫在放松状态之中。
2、The company is planning a deeper plunge into the commercial market.
这家公司正计划进一步投入商业市场。
3、There are, of course, deeper meanings in the poem.
当然，这首诗里还有更深层的含义。
4、The government was sinking deeper and deeper into the mire.
政府在泥潭中越陷越深。
deepest造句示例：
1、Please accept my deepest gratitude.
请你接受我最深的谢意。
2、May we offer our deepest sympathies on the death of your wife.
我们谨对尊夫人去世表示最深切的慰唁。
3、Her wariness of him turned to deepest mistrust.
她对他的警惕变成了极度的不信任。
4、I was stimulated to examine my deepest thoughts.
我深受启发，开始审视自己内心深处的想法。