If in a certain code, SWITCH is written as TVJSDG, which word would be written…

Concept: In letter-coding puzzles, each letter of a word is replaced according to a fixed positional pattern -- often an alternating shift, where letters at odd positions move one step forward in the alphabet and letters at even positions move one step backward (or vice-versa). The pattern is found by comparing a given word with its code letter by letter; the same pattern, applied in reverse, then decodes any other coded word.

Applying the rule to this item:

1. S (position 1, odd) is shifted one step forward to T.

2. W (position 2, even) is shifted one step backward to V.

3. I (position 3, odd) is shifted one step forward to J.

4. T (position 4, even) is shifted one step backward to S.

5. C (position 5, odd) is shifted one step forward to D.

6. H (position 6, even) is shifted one step backward to G.

This confirms the rule: odd positions shift forward by one letter, even positions shift backward by one letter. Decoding CQFZE therefore uses the reverse shift at each position:

1. Position 1 (odd): C shifts one step back to B.

2. Position 2 (even): Q shifts one step forward to R.

3. Position 3 (odd): F shifts one step back to E.

4. Position 4 (even): Z shifts one step forward to A, wrapping past Z.

5. Position 5 (odd): E shifts one step back to D.

Putting these letters together gives BREAD.

Cross-check: Re-encoding BREAD with the same rule gives B to C, R to Q, E to F, A to Z, D to E -- that is, CQFZE -- exactly the given code, confirming the decoding.