How to make a tilde.

1. Type the letter you want, click the tilde button.
    (Note that a tilde is used in lieu of a circumflex for Greek.
    Times New Roman, and most other fonts do not have a proper
    Greek circumflex, hence the substitution.)
2. Most languages that use the tilde or circumflex have a keyboard shortcut for it, go to Help > Keyboard Shortcuts, then choose the language.