In an empty column, in your 1st row of data (excluding the row with column
headings, if any), begins in row 5, enter the formula:

=ROUNDUP((ROW()-(5-1))/3,0)

and copy it down.

If the data begins in row 8, substitute an 8 in place of the 5 in the above
formula.

Convert this column of formulas to values via a column
Copy and Paste Special as 'values'.

Now you can sort using the new column as the primary key and the column that
is to be in alpabetical order as the secondary key.

Good Luck.
In an empty column

"Hitch1961" wrote:

I have a spreadsheet that has three lines of data per one subject. I need to
sort in alphabetical order the first line making sure the 2nd and 3rd stay
with the first line, same for lines 4-6, 7-9, ect...