stopping 'sed' after match found on a line; don't let sed keep checking all lines to EOF - bash

Question

I have a text file in which each a first block of text on each line is separated by a tab from a second block of text like so:
VERBS, AUXILIARY. "Be," subjunctive and quasi-subjunctive Be, Beest, &c., was used in A.-S. (beon) generally in a future sense.
In case it is hard to tell, tab is long space between "quasi-subjunctive" and "Be".
So I am thinking off the top of my head a 'for' loop in which a var is set using 'sed' to read the first block of text of a line, upto and including the tab (or not, doesn't really matter) and then the 'var' is used to find subsequent matches adding a "(x)" right before the tab to make the line unique. The 'x' of course would be a running counter numbering the first instance '1' incrementing and then each subsequent match one number higher.
One problem I see is stopping 'sed' after each subsequent match so the counter can be incremented. Is there a way to do this, since it is "sed's" normal behaviour to continue on thru without stop (as far as I know) until all lines are processed.

Answer 1

You can set the IFS to TAB character and read the line into variables. Something like:
$ while IFS=$'\t' read block1 block2;do
echo "block1 is $block1"
echo "block2 is $block2"
done < file
block1 is VERBS, AUXILIARY. "Be," subjunctive and quasi-subjunctive
block2 is Be, Beest, &c., was used in A.-S. (beon) generally in a future sense.

Answer 2

Ok so I got the job done with this little (or perhaps big if too much overkill?) script I whipped up:
#!/bin/bash
sedLnCnt=1
while [[ "$sedLnCnt" -lt 521 ]] ; do
lN=$(sed -n "${sedLnCnt} p" sGNoSecNums.html|sed -r 's/^([^\t]*\t).*$/\1/') #; echo "\$lN: $lN"
lnNum=($(grep -n "$lN" sGNoSecNums.html|sed -r 's/^([0-9]+):.*$/\1/')) #; echo "num of matches: ${#lnNum[#]}"
if [[ "${#lnNum[#]}" -gt 1 ]] ; then #'if'
lCnt="${#lnNum[#]}"
((eleN = $lCnt-1)) #; echo "\$eleN: ${eleN}" # var $eleN needs to be 1 less than total line count of zero-based array
while [[ "$lCnt" -gt 0 ]] ; do
sed -ri "${lnNum[$eleN]}s/^([^\t]*)\t/\1 \(${lCnt}\)\t/" sGNoSecNums.html
((lCnt--))
((eleN--))
done
fi
((sedLnCnt++))
done
Grep was the perfect way to find line numbers of matches, jamming them into an array and then editing each line appending the unique identifier.