5 exercises — practise choosing less versus fewer correctly when reporting technical metrics.
0 / 24 completed
1 / 24
Which sentence correctly uses "fewer" with a countable metric in a performance report?
"...the service returned fewer 500 errors during peak traffic" is correct: "errors" is a countable noun (one error, two errors), so "fewer" is required. Option B incorrectly uses "less" with a countable noun. Option C mixes "fewer" with the uncountable-style phrase "amount of". Option D incorrectly adds the article "a" before "less" with a plural noun.
2 / 24
Choose the sentence that correctly uses "less" with an uncountable metric describing system performance.
"...the API experiences less latency under load" is correct: "latency" is an uncountable noun, so "less" is the correct choice. Option B wrongly uses "fewer" with an uncountable noun. Option C incorrectly pluralizes "latency" as "latencies" while still using "less" — the plural form implies a countable reading that doesn't fit here. Option D adds the redundant, wordier "amount of".
3 / 24
Which sentence correctly distinguishes "fewer" and "less" in a single sentence comparing two related metrics, one countable and one not?
"...makes fewer database calls and consumes less memory overall" is correct: "database calls" is countable (fewer), while "memory" as a resource is uncountable (less). Option B swaps the two incorrectly. Option C incorrectly applies "fewer" to the uncountable "memory". Option D incorrectly applies "less" to the countable "calls" and wrongly pluralizes "memories".
4 / 24
Select the sentence that correctly uses "fewer than" with a specific countable figure in a release note.
"...fewer than five breaking changes..." is correct: "changes" is countable, so "fewer than" is grammatically preferred, even though "less than" is extremely common in casual usage with numbers. Option B uses the informally accepted but formally discouraged "less than" before a countable plural. Option C keeps "fewer" but drops the required plural "changes". Option D adds an ungrammatical article before "fewer".
5 / 24
Which sentence correctly uses "less" with a duration expressed as a single unit, a common exception where measurements of time, money, or distance take "less" even though the underlying noun looks countable?
"...finishes in less than ten minutes" is correct: when a plural noun is treated as a single measurement of time ("ten minutes" as one duration), "less than" is the standard, accepted form, unlike counting discrete errors or calls individually. Option B applies "fewer" as if counting individual minutes as separate countable items, which is not how durations are conventionally treated. Option C drops the required plural "minutes". Option D adds an ungrammatical article.
6 / 24
Alex: 'The deployments count is up by five this week.'
Which of the following options best completes Alex's sentence?
'Fewer' is used with *countable* nouns – in this case, 'deployments.' 'Five' is a specific number, so we need the correct form of 'few'. 'Less' describes quantities that are not countable (like time or money). Option A is incorrect because it uses 'fewer' incorrectly. Option B is wrong as it suggests a comparison with 'than', which isn't needed here.
7 / 24
Sarah (in a Slack message): 'The server response time has decreased by 20%.'
Which sentence correctly uses 'less' or 'fewer' in this context?
When referring to percentages or proportions of a quantity (like '20'%), we use 'less' with uncountable nouns. 'Time,' in this context, is considered an abstract concept and not countable. Option A incorrectly uses 'fewer' which is for items you can count. Option B attempts to force a comparison using 'than', which isn't appropriate here.
8 / 24
Ben (in a PR description): 'We've identified 23bugs in the latest release.'
Which sentence best describes the situation?
'Fewer' is used with countable nouns – 'bugs' here. Option A uses 'less' incorrectly. Option C suggests a process ('finding') rather than a count and doesn't use the correct form of the word. Option D focuses on fixing bugs, not the initial count.
9 / 24
Alex: 'The deployments count is up by five this week.'
Which of the following options best completes Alex's sentence?
'Fewer' is used with *countable* nouns – in this case, 'deployments.' 'Five' is a specific number, so we need the correct form of 'few'. 'Less' describes quantities that are not countable (like time or money). Option A is incorrect because it uses 'fewer' incorrectly. Option B is wrong as it suggests a comparison with 'than', which isn't needed here.
10 / 24
Sarah (in a Slack message): 'The server response time has decreased by 20%.'
Which sentence correctly uses 'less' or 'fewer' in this context?
When referring to percentages or proportions of a quantity (like '20'%), we use 'less' with uncountable nouns. 'Time,' in this context, is considered an abstract concept and not countable. Option A incorrectly uses 'fewer' which is for items you can count. Option B attempts to force a comparison using 'than', which isn't appropriate here.
11 / 24
Ben (in a PR description): 'We've identified 23bugs in the latest release.'
Which sentence best describes the situation?
'Fewer' is used with countable nouns – 'bugs' here. Option A uses 'less' incorrectly. Option C suggests a process ('finding') rather than a count and doesn't use the correct form of the word. Option D focuses on fixing bugs, not the initial count.
12 / 24
Alex: 'The deployments count is up by five this week.'
Which of the following options best completes Alex's sentence?
'Fewer' is used with *countable* nouns – in this case, 'deployments.' 'Five' is a specific number, so we need the correct form of 'few'. 'Less' describes quantities that are not countable (like time or money). Option A is incorrect because it uses 'fewer' incorrectly. Option B is wrong as it suggests a comparison with 'than', which isn't needed here.
13 / 24
Sarah (in a Slack message): 'The server response time has decreased by 20%.'
Which sentence correctly uses 'less' or 'fewer' in this context?
When referring to percentages or proportions of a quantity (like '20'%), we use 'less' with uncountable nouns. 'Time,' in this context, is considered an abstract concept and not countable. Option A incorrectly uses 'fewer' which is for items you can count. Option B attempts to force a comparison using 'than', which isn't appropriate here.
14 / 24
Ben (in a PR description): 'We've identified 23bugs in the latest release.'
Which sentence best describes the situation?
'Fewer' is used with countable nouns – 'bugs' here. Option A uses 'less' incorrectly. Option C suggests a process ('finding') rather than a count and doesn't use the correct form of the word. Option D focuses on fixing bugs, not the initial count.
15 / 24
Code Review Comment: 'The number of API calls to the database increased by three this morning.' Which revision is most appropriate for David to suggest?
'Fewer' is used with countable nouns (three API calls). 'Less' is used with uncountable nouns. The sentence correctly describes a countable increase. Options A and C are incorrect because they misapply the rules of 'fewer' and 'less'. Option D highlights that while technically correct, it lacks actionable information.
16 / 24
Slack Message: 'We've experienced a significant reduction in latency. We've observed less than 5ms of delay across the majority of requests.' Which sentence best reflects this message?
Latency (delay) is an uncountable metric. Therefore, 'less' is used correctly to describe a decrease in this quantity. Option A misapplies 'fewer'. Options B and C are incorrect because they suggest specific numerical values or misinterpret the message's core meaning.
17 / 24
PR Description: 'The system now supports processing up to fewer than 100 concurrent users.' Which of the following best completes this description?
'Fewer' is used with a countable number (less than 100). The sentence describes a defined limit. Options A and B are overly reactive; option C reflects a reasonable interpretation of the statement's meaning, while Option D misinterprets the comparison.
18 / 24
Code Review Comment: 'The duration of the database query increased by less than one second.' Which revision best suggests a follow-up action?
'Less' is used with time as a single unit (less than one second). The sentence describes an increase in query duration. Options A and D are incorrect interpretations; option C reflects a potential misunderstanding of the metric.
19 / 24
Michael: 'We've reduced the average latency by approximately 15ms.' Which sentence correctly uses 'less' or 'fewer' in this context?
Michael's message is about a *reduction* in latency (a measurement). 'Less than' correctly describes a quantity that is below a specified value – in this case, 15ms. The other options misinterpret the meaning or use 'less' incorrectly in the context of latency.
20 / 24
Sarah is writing a comment for a pull request. The team has deployed a new version of the application and she wants to describe the changes in terms of performance metrics. Which sentence accurately uses 'less' or 'fewer'?
'Less' is used to describe a quantity that is not countable – in this case, 'downtime'. 'Fewer' is for countable nouns like 'errors'. Option 2 correctly uses 'less' because 'improvement' (a rate) describes a decrease in downtime. Options 3 and 4 use percentages incorrectly.
21 / 24
David is reviewing a code change and notices the team has reduced memory usage. Which sentence best reflects this situation?
'Less' is appropriate when referring to a quantity that isn't countable – in this case, memory. 'Fewer' is used for things you can count (e.g., number of processes). Options 2 and 3 use 'increased' incorrectly, and option 4 misinterprets the context.
22 / 24
John is giving a standup update. He wants to describe the number of support tickets resolved during the day. Which sentence correctly uses 'less' or 'fewer'?
'Less' is used when referring to an uncountable quantity (incidents). 'Fewer' is for countable nouns (tickets). Option 3 incorrectly uses 'increased', and option 4 refers to a complaint which isn't quantifiable in this way.
23 / 24
Emily is writing a Slack message about the performance of a newly deployed API endpoint. Which sentence uses 'less' or 'fewer' correctly?
'Less' is appropriate for describing a duration (latency). 'Fewer' is used for countable nouns like 'requests'. Option 2 uses the correct phrasing to describe reduced latency. Options 3 and 4 misinterpret the context of API performance metrics.
24 / 24
Mark is creating a PR description for a database optimization project. He wants to describe the impact on query execution time. Which sentence correctly uses 'less' or 'fewer'?
'Less' is suitable for describing a duration (milliseconds). 'Fewer' is used when referring to countable items like 'queries'. Option 2 accurately uses 'less' to describe a decrease in slow queries. Options 3 and 4 misuse the terms.
What will I practise in ""Less" vs "Fewer" with Technical Metrics — IT Grammar Exercise"?
Practise choosing "fewer" with countable technical metrics like errors and requests versus "less" with uncountable ones like latency and bandwidth, in
How many exercises are in this module?
This module has 24 multiple-choice exercises, each with instant feedback and a full explanation of the correct answer.
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Every exercise is written by the CoderSlingo team, drawing on real workplace English used in IT roles, then reviewed for accuracy and clarity.