Foundations of English Literacy:
Hickey Method Website

To add a suffix to a word ending in -ie:

1) to add –ing: change the -ie to y, then add –ing. tie > tying

2) to add s – just add it: tie > ties

3) to add –ed: drop the -e and add –ed:

tie > tied, lie, lies, lied, lying

"My Party Dress"