A sentence can be long and well formed, or short and incorrectly joined. The problem is not simply its length. If two complete clauses run together without a suitable connection, the reader has to work out where one idea ends and the next begins.
The clauses and punctuation sections of Jobin Thomas’s PTE Grammar Lab explain this through independent clauses, dependent clauses, conjunctions and editing exercises. This guide shows how to repair a sentence while keeping its intended relationship between ideas.
Find the complete clauses first
A complete independent clause can stand as a sentence: “The room was noisy.” Another is “Maya moved to the library.” Placing them together without a suitable join creates a problem: “The room was noisy Maya moved to the library.”
Identify both subject–verb pairs before adding punctuation. That helps you see whether you have two complete ideas, or whether one part depends on another. “Because the room was noisy” leaves the reader expecting a main clause.
Choose a repair that suits the message
You can separate the ideas into two sentences: “The room was noisy. Maya moved to the library.” You can join related independent clauses with a semicolon: “The room was noisy; Maya moved to the library.” Or you can use a suitable conjunction.
For example, “The room was noisy, so Maya moved to the library” states a result. Use “so” only if that cause-and-result relationship is intended. A grammatical connector should not add an explanation that the original information does not support.
Original contrast example
Draft: “The article was brief, it contained several useful examples.”
Repair: “The article was brief, but it contained several useful examples.”
Another option: “Although the article was brief, it contained several useful examples.”
Both versions express contrast. The comma alone in the draft does not properly join the two independent clauses.
Do not treat “however” exactly like “but”
“However” can signal a contrast, but it does not join independent clauses in the same way as the coordinating conjunction “but.” Compare “The task was difficult, but I completed it” with “The task was difficult; however, I completed it.”
Two sentences are also possible: “The task was difficult. However, I completed it.” Choose the structure you can control accurately and that fits the task you are practising. More punctuation does not automatically make writing more advanced.
Repair the sentence in two different ways
Draft: “The library was busy, however, a quiet study room was available.”
Option 1: “The library was busy; however, a quiet study room was available.”
Option 2: “The library was busy, but a quiet study room was available.”
You could also use two sentences. Notice that the contrast stays the same while the joining structure changes.
Check that the repair has not created a fragment
Adding “although” or “because” makes a clause dependent. “Although the lesson was useful” is not a complete sentence on its own in ordinary formal prose. Complete the thought: “Although the lesson was useful, I needed more practice.”
Read both sides of the join after editing. If you use a semicolon, the clauses on either side should be able to stand independently. If you use a dependent opening clause, check that a main clause follows it.
Practise on one paragraph, then transfer the skill
Take a short paragraph from your own writing and mark each complete clause. Check how the clauses connect. Repair one awkward join, then explain whether the connection shows addition, contrast, cause or another relationship.
Record the original join, your correction and why it works. “Changed comma + however to semicolon + however” gives you a specific pattern to notice in your next draft.
Explore PTE Grammar — Course 1 for the course connected to PTE Grammar Lab. Compare its outline with the sentence patterns you want to practise, and use your next writing attempt to check whether you can apply the correction independently.
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PTE Grammar — Course 1
Explore the complete course outline and related practice topics.
Source: PTE GR 100.epub, Jobins Training. Examples labelled original or illustrative were written for this article. Independent exam preparation; no affiliation with or endorsement by the examining body. Practice does not predict an official score.