Hi Eric,
Pages creates two types of documents.
In a Word Processing document, text is placed in the document body, where it flows from one page to the next, creating a 'next page' as needed.
Setting the preference to 2 columns does not change the facts above. ALL of the text in the document body remains a single stream.
In your case, that means when the English column is filled, additional text would start to fill the second (Spanish) column on the same page. If there is already Spanish text in that column, it will be pushed down to the (left column of the) next page.
To avoid this shift, you would need to insert a column break at the end of the English text on each page, and a page break at the end of the Spanish text on that page.
Doable, but tedious for a long document, or for editing the text in either column, and, going by your description, it is not the page type of Pages document you are using.
In a Pages Page layout document, there is no document body to contain the text.
Text in this document type must be placed in containers, such as Text Boxes.
Text boxes may be linked to form a 'thread' which a long string of text can follow to continue on new (added) pages.
New pages in this type of document are added by the user, as they are needed, and the text boxes on the new pages must be linked with the previous box in the thread to accept the continuation of text in that thread.
This is likely the document type you are using, and I think it it is the better choice for what you want.
Here's an illustration:
To create this example, I opened a new Page Layout document using the Blank page layout template.
I then added a text box to the empty page, resized the box to fit on the left side of the page, leaving margin space on it's left and a smaller space between its right side and the vertical centre of the page.
I then duplicated the text box and moved the copy to the right side of the page, aligning the tops of the two boxes, and placing each at close to the same distance from the vertical centre of the page.*
Before adding any text to the boxes, I selected the page thumbnail in the left sidebar and used the Duplicate selection menu item in the Edit menu to make a new page identical to the first.
Step 2: Add text, making sure it ran past the bottom of the box
I pasted some Lorem text into the left box, repeating the paste enough times to ensure the text would overfill the box, then picked the beginning of a sentence still visible in the box and entered enough return characters to push that sentence (and the text below it) past the bottom of the text box.
2A: Repeated the above with the second box, using a google translation into Spanish of the Latin text used above, and pushing the same sentence to the second page.
Step 3: Creating the thread.
This is a simple part:
Select the first text box. You will see a set of squares appear at the corners of the box and a larger circle at the centre of the top edge of the box. Click the circle to start a thread, and it will be filled (likely with green) and will show a 1 in white.
Scroll down to the second page. Select the text box on the left, then click the larger circle at top centre to add it to the thread.
The circle will be filled with the same colour as the first, indicating it is in the same thread, and will contain a white 2, indicating it is the second table in this thread.
And the text, pushed off the bottom of the first table will immediately appear in this box.
Repeat the same steps with the tables on the right half of each page, starting with the one on Page 1. You'll get the same results, but with a different colour fill in the large circle (likely Red).
When filling in the text boxes, use repeated returns after the last text wanted on 'this page' (the page you are working on) to push the text for the next page to the next page.
Regards,
Barry