In Sentence Completion questions, you are given a set of sentences with missing words. Your task is to complete these sentences using words taken directly from the reading passage. You will be told the exact number of words you can use (e.g., ONE WORD AND/OR A NUMBER, NO MORE THAN TWO WORDS).

The Core Challenge:
This is not a test of your creativity. It is a test of your ability to:

1. Understand the specific information in a sentence.
2. Locate that information in the passage.
3. Identify the exact word(s) that fit grammatically and meaningfully into the gap.

Crucial Distinction from Other Tasks:

• vs. True/False/Not Given: This task is about finding facts, not opinions.
• vs. Summary Completion: Sentence Completion questions are often more scattered throughout the text and test your ability to find specific, discrete pieces of information.

7-Step Strategy for Sentence Completion

Step 1: Read the Instructions Meticulously
This is non-negotiable. You must check the word limit. If you write three words when the instruction says “NO MORE THAN TWO WORDS,” your answer will be marked incorrect, even if the meaning is right.

Step 2: Analyze the Incomplete Sentences
Read the sentences carefully before looking at the text. Your goal is to predict the type of word(s) needed for each gap.

• What part of speech is needed? (Noun, verb, adjective, adverb?)
• Is it likely a name, a number, a place, or a concept?
• Pay close attention to the grammar before and after the gap. Does it require a singular/plural noun? An -ing verb?

Step 3: Identify Keywords for Scanning
Underline the key “meaning” words in each sentence (nouns, names, dates, verbs). These will be your anchors for scanning the passage. The words immediately around the gap are often the most important.

Step 4: Locate the Relevant Area in the Text
Scan the passage for the keywords you identified. The questions will follow the order of the text. Use names, dates, and unique terminology to find the correct section quickly.

Step 5: Read the Text Intensively
Once you find the area, read the relevant sentences carefully. Your aim is to find a word or phrase that conveys the same meaning as the incomplete sentence.

Step 6: Select the Correct Word(s)
When you find the answer, check it against your prediction from Step 2.

• Does it fit grammatically?
• Does it make logical sense?
• Does it obey the word limit?
  Important: The answer must be the exact word(s) from the passage. Do not change the form of the word (e.g., from ‘succeeded’ to ‘success’).

Step 7: Finalize Your Answer and Move On
Write your answer clearly. If you are struggling, make an educated guess based on the grammar and meaning, and move on to the next question.

IELTS Reading Practice: Sentence Completion

Passage: The History of the Telegraph

The invention of the telegraph in the 1830s and 1840s marked a profound turning point in human history, revolutionizing communication. While several inventors contributed to its development, it is Samuel Morse who is most widely credited with creating a practical and commercially viable system in the United States. His key innovation was not the hardware alone, but the efficient encoding system known as Morse code.

Before a successful transatlantic cable was laid, telegraph messages could only be sent across land or, with difficulty, across shorter stretches of water. The first durable transatlantic telegraph cable was finally completed in 1866, after several failed attempts. This achievement effectively shrank the world, allowing messages that once took weeks to deliver by ship to be transmitted in a matter of minutes. The primary users of this service were governments, news agencies, and large businesses, as the cost was prohibitively high for the general public. A ten-word message could cost as much as fifty dollars, a small fortune at the time.

The telegraph’s dominance was eventually challenged by the invention of the telephone. Although the telephone offered a more intuitive and immediate form of communication, the telegraph did not become obsolete overnight. In fact, for many decades, both technologies coexisted, serving different needs. The telegraph remained the preferred method for concise, non-urgent business communication and official dispatches well into the 20th century.

Questions:
Complete the sentences below.
Choose NO MORE THAN TWO WORDS AND/OR A NUMBER from the passage for each answer.

1. Samuel Morse is best known for developing a telegraph system that was both practical and …………………. .
2. The successful …………………. telegraph cable was laid in 1866.
3. The high cost of sending a transatlantic message meant it was mainly used by governments and big …………………. .
4. A ten-word telegram in the 19th century could have a price tag of up to …………………. .
5. Even after the telephone was invented, the telegraph was still used for …………………. business communication.

Step-by-Step Demonstration Table

Let’s demonstrate the process for a trickier question.

Question 3: The high cost of sending a transatlantic message meant it was mainly used by governments and big …………………. .

• Step 2: The sentence structure “…governments and big …” suggests we need a noun, specifically a type of organization or entity. “Big businesses” is a common collocation.
• Step 3: Keywords: high cost, transatlantic, governments.
• Step 4: These keywords lead to the second paragraph.
• Step 5: Text: “The primary users of this service were governments, news agencies, and large businesses…”
• Step 6: The sentence says “big,” the text says “large.” These are synonyms. The correct noun is businesses. It fits grammatically and is within the word limit.

Analysis: This is a common trap. The word in the question might be a synonym of the word in the text. Your job is to find the correct noun from the passage that matches the meaning, not the adjective.

Now, try to complete the rest. The answers are below.

Answers:

1. commercially viable (Paragraph 1: “practical and commercially viable system”)
2. transatlantic (Paragraph 2: “The first durable transatlantic telegraph cable was finally completed in 1866”)
3. businesses (Paragraph 2: “The primary users… were governments, news agencies, and large businesses”)
4. fifty dollars (Paragraph 2: “A ten-word message could cost as much as fifty dollars”)
5. non-urgent (Paragraph 3: “The telegraph remained the preferred method for concise, non-urgent business communication”)