必要, 必用, ひつよう
NA-adjective, 必用 can imply has to be used rather than is just needed
1. necessary, needed, essential, indispensable
2. necessity, need, requirement
歯医者に行く必要はないですよ。
が
Particle
1. indicates the subject of a sentence
literary in modern Japanese; usu. written as ヶ in place names
2. indicates possession
Conjunction
3. but, however, (and) yet, though, although, while
4. and
5. used after an introductory remark or explanation
ある, 有る, 在る
Godan verb, Intransitive, See 居る・いる・1, Usually in kana, usu. of inanimate objects
1. to be, to exist, to live
2. to have
3. to be located
4. to be equipped with
5. to happen, to come about
悪いけどほかに用事があるの。
ある, 或る, 或
Pre-noun adjectival (rentaishi), Usually in kana
a certain ..., some ...
ある学生に会うところです。