An important difference between presupposition and entailment is that presupposition，unlike entailment，is not vulnerable to negation. That is to say, if a sentence is negated, the original presupposition is still true.

判断题Linguistic forms having the same sense may have different references in different situations while linguistic forms with the same reference always have the same sense.

判断题“The student” in the sentence “The student liked the linguistic lecture.”，and “The linguistic lecture” in the sentence “The linguistic lecture liked the student.”belong to the same syntactic category.

判断题A compound is the combination of only two words.

判断题In English， long vowels are also tense vowels because when we pronounce a long vowel such as i： ，the larynx is in a state of tension.

判断题In the history of any language the writing system always came into being before the spoken form.