Does the DET test grammar and vocabulary?
Yes, but not as a separate multiple-choice grammar paper. Open responses are evaluated partly through vocabulary, grammar, spelling, clarity, and fluency; completion tasks also depend on spelling and context.
Start with sentence structure, then tense and agreement, and finally range and precision. A correct, direct sentence is more useful than a complex sentence you cannot control.
| Error group | Typical symptom | First action |
|---|---|---|
| Sentence structure | Fragments, run-ons, unclear main clause | Find the subject and verb; split uncontrolled sentences |
| Grammar relationships | Agreement and tense shifts | Check the true subject and timeline |
| Word form and collocation | Wrong part of speech or preposition | Identify the function of the gap first |
| Vocabulary range | Repeated vague words | Learn precise words in topic-based phrases |
Which DET question types use grammar and vocabulary?
Map each skill to a real task. Official frequency ranges can vary within the adaptive test.
| Question type | Main language demand | What to check |
|---|---|---|
| Read and Select | Real-word recognition and spelling | Word families and plausible spelling |
| Fill in the Blanks | Meaning, position, and spelling | Part of speech first, exact word second |
| Read and Complete | Words in passage context | Meaning, inflection, and full spelling |
| Listen and Type | Word order, function words, endings | Articles, prepositions, plurals, and tense endings |
| Writing tasks | Relevant development and controlled language | Sentence boundaries, tense, word form, spelling |
| Speaking tasks | Clear content and fluent delivery | Cover each prompt part with language you can use accurately |
What are 18 common DET grammar and vocabulary errors?
Track the three errors you make most often for one week. That is easier to measure than changing topics every day.
| # | Error | Before → better | Likely tasks |
|---|---|---|---|
| 01 | Missing article before a singular count noun | has important role → has an important role | Writing |
| 02 | Using the for a general concept | the education matters → education matters | Writing, speaking |
| 03 | Number mismatch | many student → many students | Completion, dictation |
| 04 | Subject–verb mismatch | the quality … are → the quality … is | Writing, speaking |
| 05 | Count/non-count confusion | many information → much information | Completion, writing |
| 06 | Present perfect with a finished time | have visited last week → visited last week | Writing, speaking |
| 07 | Unmotivated tense shifts | was … is … went → keep one timeline | Writing, speaking |
| 08 | Mixed real conditional | if I will practise → if I practise, I will… | Writing, speaking |
| 09 | Unequal comparison | schedule vs schools → schedule vs that of schools | Writing, speaking |
| 10 | -ing/-ed adjective confusion | I am boring → I am bored | Description tasks |
| 11 | Wrong part of speech | respond clear → respond clearly | Completion, writing |
| 12 | Inflected verb after a modal | can improves → can improve | Completion, production |
| 13 | Irregular participle error | have wrote → have written | Completion, writing |
| 14 | Translated preposition | responsible of → responsible for | Completion, production |
| 15 | Dependent clause as a sentence | Because it was late. → add a main clause | Writing |
| 16 | Comma splice | It was hard, I continued. → add a conjunction or split | Writing |
| 17 | Repeated vague vocabulary | good / thing / important → precise nouns and verbs | Writing, speaking |
| 18 | Missing function words or endings | missing a / the / -s / -ed → final replay check | Listen and Type |
How do I check articles and subject–verb agreement?
For articles, identify the noun and decide whether it is singular, countable, specific, or general. For agreement, ignore intervening phrases and find the true subject.
- Use a/an for one non-specific singular count noun: a student, an idea.
- Use the when the reader can identify the noun: the student mentioned earlier.
- General plural and non-count nouns often take no article: Students need feedback; Education takes time.
- Remove modifiers before checking agreement: The quality of the examples is important.
Before: Technology has important role in education.
Better: Technology has an important role in education.
Role is a singular count noun used non-specifically, so it needs an.What tense and conditional errors are common on the DET?
Set the timeline before you write or speak: when did it happen, does it continue now, and is the condition real or hypothetical?
| Purpose | Useful form | Example |
|---|---|---|
| Finished past event | Past simple | I joined the club last year. |
| Past event linked to now | Present perfect | I have learned to manage my time. |
| Real future condition | If + present, will + verb | If I practise daily, I will improve. |
| Unreal present condition | If + past, would + verb | If I had more time, I would read more. |
Before: I have visited the museum last Saturday.
Better: I visited the museum last Saturday.
Last Saturday is a completed past time.How do comparisons and -ing/-ed adjectives work?
Compare equivalent things. Use -ing for something that causes a feeling and -ed for the person who experiences it.
- Online classes are more flexible than fixed schedules.
- This was the most useful part of the course.
- The lecture was confusing; the students were confused.
Before: The schedule of online courses is more flexible than traditional schools.
Better: The schedule of online courses is more flexible than that of traditional schools.
The sentence now compares one schedule with another.How do I choose a word form in DET completion tasks?
In Fill in the Blanks and Read and Complete, decide whether the position needs a noun, verb, adjective, or adverb before choosing the exact word.
| Clue | Question | Example |
|---|---|---|
| After a determiner | Do I need a noun, and what number? | a decision / several decisions |
| After be | Adjective, noun, or progressive form? | is useful / is growing |
| After a modal | Is the verb in its base form? | can improve |
| Adverb position | Does it modify a verb or adjective? | respond clearly |
Affixes can narrow the options, but the final word must fit the whole sentence and be a real English spelling. Study word families in context: decide, decision, decisive, decisively.
How do I fix fragments and comma splices?
Sentence-boundary errors often hurt readability more than a small article or spelling error.
Before: Because the library closes early.
Better: I study online because the library closes early.
A because-clause needs a main clause.Before: The test was challenging, I stayed calm.
Better: The test was challenging, but I stayed calm.
Use a conjunction, semicolon, or full stop instead of a comma alone.How should I learn DET vocabulary so I can use it?
Store vocabulary as a topic, a collocation, and a complete example rather than as an isolated translation. Reuse the same group in reading, listening, writing, and speaking.
| Question type | Vocabulary focus | Practice method |
|---|---|---|
| Read and Select | Real spelling, common affixes, plausible nonwords | Verify uncertain words instead of guessing from sound alone |
| Fill in the Blanks | Position, collocation, and context | Choose the part of speech before the exact word |
| Listen and Type | Function words, weak forms, endings | Repeat by phrase and check small words last |
| Writing and speaking | Precise synonyms and topic phrases | Prepare five useful collocations per topic and use each in a sentence |
Learn prepositions with the word they complete—responsible for, benefit from, focus on. For a dictation error, save the sound, correct spelling, and original sentence together.
What is a useful 20-minute DET grammar and vocabulary routine?
Use the same sequence each day so you can see whether recurring errors decrease.
- 5 minutes: review five errors you actually made yesterday.
- 5 minutes: complete one small drill and explain each choice.
- 7 minutes: write 80–120 words on a DET-style topic using today's target.
- 3 minutes: check sentence boundaries, tense, word form, and spelling in that order.
Frequently asked questions
Does the DET have a separate grammar test?
No. Grammar, vocabulary, spelling, and sentence control are used across completion, dictation, writing, and speaking tasks.
How many words do I need for the DET?
DET does not publish a required vocabulary count. Learn high-frequency and academic words through families, collocations, topics, and real task use.
Do more complex sentences always improve a writing score?
No. Variety can help when it is accurate, but uncontrolled complexity creates fragments, tense shifts, and run-ons. Clarity comes first.
Official sources and verification note
This guide supports study and preparation; it does not replace official Duolingo English Test policy. Recheck the official pages before your test.
- How the Items Are ScoredOfficial scoring information for DET tasks and open responses.
- Test StructureCurrent task names, frequency ranges, and adaptive-test structure.
- Assessing Vocabulary on the DETResearch on vocabulary measurement in Read and Select and Fill in the Blanks.
- DET Technical Manual 2025Technical evidence about constructs, scoring, reliability, and validity.