5 exercises — practise parallel structure and inversion with not only... but also in technical reports.
0 / 5 completed
1 / 5
Which sentence correctly uses "not only... but also" with parallel structure to describe a caching layer's benefits?
"Reduces not only latency but also database load" is correct: both elements joined by "not only... but also" are parallel noun phrases (latency / database load) functioning as objects of the same verb "reduces", which is the cleanest and most idiomatic parallel structure. Option A breaks parallelism by adding a redundant subject-verb ("it reduces") after "but also", turning the second element into a full clause instead of matching the first element's noun-phrase structure. Option C misplaces "also" awkwardly after "database load" instead of before it. Option D incorrectly triggers subject-auxiliary inversion (appropriate only when "not only" begins the sentence and directly precedes a full clause) while also breaking parallel structure between the two joined elements.
2 / 5
Which sentence correctly applies subject-auxiliary inversion after a sentence-initial "not only"?
"Not only did the outage affect the API" is correct: when "not only" opens a sentence and is followed by a full clause, standard English requires subject-auxiliary inversion (like a question), inserting "did" before the subject "the outage" and using the base form "affect" — this is the same inversion pattern seen after other negative/restrictive fronted elements like "never" or "rarely". Option B fails to invert at all, leaving "not only the outage affected" in normal declarative order, which is ungrammatical after a fronted "not only" clause. Option C inverts incorrectly, placing the verb before the subject without the required auxiliary "did". Option D places "did" after the subject instead of before it, which is not the correct inversion order.
3 / 5
Choose the sentence with correct parallel structure between the "not only" and "but also" elements describing a tool's features.
"Catches not only syntax errors but also formatting inconsistencies" is correct: both "syntax errors" and "formatting inconsistencies" are parallel noun phrases serving as direct objects of the single verb "catches", positioned identically after each correlative element. Option A places "not only" before the verb "catches", which then requires the second element after "but also" to also contain a verb for true parallelism (it does not), creating a structural mismatch. Option C compounds this by inserting an unrelated verb "is" after "but also", producing a nonsensical, non-parallel clause. Option D moves "also" to the end, separating it from "but", which breaks the fixed correlative pair "but also" and reads as non-standard.
4 / 5
Which sentence correctly uses "not only... but also" to join two full clauses without inversion, since "not only" is not sentence-initial?
Option A is correct: because "not only" appears mid-sentence (after the subject "the migration"), no subject-auxiliary inversion is required — inversion is only triggered when "not only" is the very first element of the sentence, directly followed by a clause. Each clause here keeps normal declarative word order, and "but also" smoothly introduces the second clause with its own subject "it". Option B incorrectly adds inversion ("did it take") even though "not only" is not sentence-initial, which is unnecessary and ungrammatical here. Option C moves "not only" to the front of the sentence but fails to apply the inversion this position requires. Option D breaks parallel structure by pairing "longer than expected" (an adjective phrase) with "it introduced new bugs" (a full clause) after "not only... but also".
5 / 5
A postmortem report begins: "_____ did the monitoring alert fire late, but it also pointed to the wrong service." Choose the correct fronted correlative.
"Not only" is the correct correlative conjunction that pairs with "but also" later in the sentence and correctly triggers the subject-auxiliary inversion seen here ("did the monitoring alert fire"). "Not just" (option B) is a near-synonym in meaning but is not the standard fixed correlative pair with "but also" in formal grammar, and while informally sometimes used, it is not the textbook-correct choice being tested. "Also not" (option C) is not a recognized correlative structure and does not pair with "but also" at all. "Not either" (option D) is used with "or" in negative agreement contexts ("I don't like it either"), not as a correlative with "but also".