Maybe not, partner. Assistant is a plain word, the accent falls on the penultimate syllable. Some people are not aware of these grammatical issues. But it is very simple. When we utter the words we will doing repetitive separations. Each coup voice (a-yu-dan-te) is a syllable. Normally one of the syllables is pronounced with more intensity. That is what carries the accent that can be stressed only or spelling. Some words do not carry this accent because they are unstressed and have a monotonous pronunciation, without a syllable that stands out as in the beginning of the composite anthroponyms, Ana Maria, Buenos Aires, in articles, Assistant, possessive adjectives, our or father, the first element of the complex number, forty-two and many other. All grammars have its complexity but it is worth to get to know them.