"There is a laptop."
Translation:هُناك لاب توب.
no, it can't come at the end of the sentence with only these two words. So "لابتوب هناك" is wrong. A linguistically acceptable alternative would be "يوجد لابتوب هناك", which has the same meaning but with a verb at the beginning instead of a name. Another acceptable alternative is "اللابتوب هناك", meaning " the laptop is there" as a nominal sentence should begin with a definite word or equivalent.