Bonjour !
Answer:
<em>In French, we use Bonjour to say hello to everyone.</em>
<em>Bonjour Mary ! </em>
<em>Bonjour John ! </em>
<em>Bonjour monsieur ! </em>
<em>Bonjour madame ! </em>
<em>Bonjour mademoiselle ! </em>
<em />
<em>It fits for an old person, a young one, a man, a woman, your boss or a dear friend.</em>