dread它的词性比较多,可以做名词,动词,还有形容词,而dreadful 就是形容词.我补充一下：dread作动词时,后面一般跟动名词,不定式,或者that从句.
She dreads going to the dentist.她怕去看牙医.
He dreads to see her again.他怕再见到她.当dead和deadful都做形容词的时候,用法就差不多一样呢,what a dread storm.多么可怕的一场暴风雨 .
tiger is a dreadful animal.老虎是一种可怕的动物.嘿嘿