Not having a glossary at hand, I copied your post and used the two paragraphs there.
My Glossary words are "I've" and "How"
Make sure each word and its definition are separated by a tab. The definition must be a single paragraph, and end with a single return.
When the glossary has been edited to fit that description:
Select all of the words and definitions
Go Format (menu) > Table > Convert Text to Table
This will give you a two column table, with the words in Column A and their definitions in Column B.

To sort the table:
Open the Inspector and choose the Table Inspector. Select a cell in column A of the table, then choose Sort Ascending from the pop-up menu in the Edit rows & Columns section:

You can use the table just for sorting, then use the same menu path to convert the table back to text, or you could sort the table, then keep the glossary in a table format, adjusting the width of column A to fit the longest word and the width of column B to fit the rest of the page width.
Here (after sorting), I've made those adjustments to the table and added a Header row (using the Headers and Footers controls just above the Edit... section) for a title (Glossary).

Regards,
Barry