In Phonemes, you cannot select and delete content in the Phonological Features field. Instead, you use the Choose Phonological Features dialog box to remove or replace a phonological feature.
In the Navigation Pane, click Grammar, and then click Phonemes.
In the Phonemes pane, click the phoneme that has the phonological feature you will remove.
In the Phoneme pane, click the Phonological Features field, and then click the ellipsis button that appears.
The Choose Phonological Features dialog box appears.
Click the feature you want to remove.
Do one of the following in the Value column:
To remove a feature, select <n/a>. Then, choose a different feature, if necessary.
To replace the current feature, select a different value.
Click OK.
The feature is removed from or changed in the Phonological Features field.