-도록

Etymology
The suffix also appeared as the modern form as far back as in the fifteenth century.

The Idu spelling is attested from earlier.

Suffix

 * 1) so that, so as to:
 * 2) to:
 * 3) until:
 * 1) to:
 * 2) until:
 * 1) until:

Usage notes

 * is more common in the written language.
 * is mostly interchangeable with with no significant difference in meaning except in the third sense, where  would be considered grammatically incorrect.