6.3 Clause Structure: Relative, Adverbial, and Noun Clauses

English Comprehension Level ECL

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1 Chapter 1: ECL Test Overview, Administration & Policies

1.1 Overview of ECL, DLIELC Governance, and Security Cooperation Context 1.2 Test Formats: 100-Item Paper/Pencil vs. CAT (Computer Adaptive Test) 1.3 Test Administration, Security, TCO Roles, and ALCPT Screening 1.4 ECL Scoring, Validity (180 days), Retake Policy (30-day OCONUS wait), and Course Requirements (MASL)

2 Chapter 2: Listening — Short Statements & Restatements

2.1 Time, Date, and Number Comprehension 2.2 Location, Directions, and Spatial Relationships 2.3 Actions, Activities, and Everyday Routines 2.4 Paraphrasing and Synonym Restatements in Listening

3 Chapter 3: Listening — Conversations & Dialogs

3.1 Two-Person Dialogs: Clarifications, Questions & Answers 3.2 Identifying Speaker Intent, Feelings, and Preferences 3.3 Informal Idioms, Phrasal Verbs, and Expressions in Speech 3.4 Requesting Information, Making Suggestions, and Giving Advice

4 Chapter 4: Listening — Announcements & Brief Talks

4.1 Following Oral Instructions and Commands 4.2 Public & Official Announcements (Base, Airport, Weather, Emergency) 4.3 Understanding Brief Reports, Orientation Talks, and Short Lectures 4.4 Inferring Main Idea and Key Details from Spoken Audio

5 Chapter 5: Reading — Vocabulary in Context & Collocations

5.1 Everyday & General Vocabulary in Context 5.2 Common Collocations and Prepositional Phrases 5.3 Antonyms, Synonyms, and Contextual Clues 5.4 Military-Adjacent & Operational Context Vocabulary

6 Chapter 6: Reading — Grammar & Sentence Structure

6.1 Verb Tenses, Aspects, and Voice (Active vs. Passive) 6.2 Modals, Conditionals, and Subjunctive Structures 6.3 Clause Structure: Relative, Adverbial, and Noun Clauses 6.4 Comparatives, Superlatives, and Adjective/Adverb Modifiers 6.5 Pronoun Reference, Agreement, and Determiners

7 Chapter 7: Reading — Sentence Completion & Mechanics

7.1 Completing Single-Sentence Contexts with Correct Part of Speech 7.2 Sentence Connectors, Transitions, and Logical Cohesion 7.3 Parallel Structure, Subject-Verb Agreement, and Word Order

8 Chapter 8: Reading — Passage Comprehension & Procedural Reading

8.1 Locating Explicit Facts and Details in Short Passages 8.2 Main Idea, Title Selection, and Author's Purpose 8.3 Drawing Logical Inferences and Conclusions 8.4 Reading Instructional, Procedural, and Operational Notices

9 Chapter 9: Test-Day Strategy & Study Plan

9.1 Listening Section Test-Taking Strategies (One-Hearing Rule) 9.2 Reading Section Test-Taking Strategies & Time Allocation 9.3 6-Week Study Plan and Score Target Optimization

6.3 Clause Structure: Relative, Adverbial, and Noun Clauses

Key Takeaways Explain This Topic AI

Defining relative clauses provide essential identifying information, while non-defining relative clauses provide extra information and are set off by commas.

Reduced relative clauses omit the relative pronoun and the verb 'to be', leaving behind a concise participle phrase.

Adverbial clauses modify verbs and are introduced by subordinating conjunctions; they must be carefully distinguished from prepositional phrases.

Noun clauses function as subjects or objects within sentences, often appearing as embedded questions that require statement word order.

Last updated: July 2026

In the third part of this chapter, we explore the architecture of complex sentences: clause structures. The ECLT heavily features long, intricate sentences in its reading comprehension passages. To accurately extract meaning and identify grammatical errors, you must be able to break these sentences down into their component clauses. A clause is a group of words containing a subject and a verb. Independent clauses can stand alone as complete sentences, whereas dependent (or subordinate) clauses cannot. In this section, we will focus on three major types of dependent clauses: relative clauses, adverbial clauses, and noun clauses.

We begin with Relative Clauses (also known as adjective clauses), which modify nouns or pronouns. These clauses are introduced by relative pronouns such as 'who', 'whom', 'whose', 'which', and 'that'. 'Who' and 'whom' are used for people ('who' as a subject, 'whom' as an object). 'Which' is used for things and animals. 'That' can be used for people, things, and animals in defining clauses. 'Whose' indicates possession.

It is critical to distinguish between Defining and Non-defining Relative Clauses . A defining (or restrictive) relative clause provides essential information that identifies which specific person or thing is being discussed. These clauses are not separated by commas. For example, 'The students who study hard will pass the exam.' If you remove the clause, we no longer know which students will pass. A non-defining (or non-restrictive) relative clause provides extra, non-essential information about a noun that is already specifically identified. These clauses must be set off by commas. For example, 'Dr. Smith, who studies hard, will pass the exam.' In formal English, 'that' is only used in defining clauses; you cannot use 'that' after a comma in a non-defining clause.

Another advanced concept frequently tested is the Reduced Relative Clause . When a relative pronoun acts as the subject of the clause and is followed by a form of the verb 'to be', both the pronoun and the 'be' verb can often be omitted, leaving behind a participle phrase. For example, 'The woman who is standing by the door is my sister' can be reduced to 'The woman standing by the door is my sister.' Similarly, a passive relative clause can be reduced: 'The car which was damaged in the accident was sold' becomes 'The car damaged in the accident was sold.' Recognizing these reduced forms is vital for identifying sentence subjects and main verbs.

Next, we examine Adverbial Clauses . These dependent clauses function as adverbs, modifying a verb, an adjective, or another adverb by answering questions like when, why, how, or under what conditions. They are introduced by subordinating conjunctions. Adverbial clauses of time are introduced by words like 'when', 'while', 'before', 'after', 'since', and 'until'. Adverbial clauses of reason are introduced by 'because', 'since', and 'as'. Adverbial clauses of concession or contrast are introduced by 'although', 'even though', 'though', 'whereas', and 'while'. Adverbial clauses of condition are introduced by 'if', 'unless', and 'provided that'.

A common testing point on the ECLT involves the correct use of conjunctions versus prepositions. Subordinating conjunctions (like 'although' and 'because') must be followed by a full clause with a subject and verb (e.g., 'Although it was raining, we went out'). Prepositions with similar meanings (like 'despite' or 'because of') must be followed by a noun phrase or gerund, not a full clause (e.g., 'Despite the rain, we went out'). Confusing these two structures is a classic grammar error tested on exams.

Finally, we turn to Noun Clauses . A noun clause is a dependent clause that functions as a noun. Because it acts as a noun, it can serve as the subject of a sentence, the object of a verb, or the object of a preposition. Noun clauses are often introduced by words such as 'that', 'whether', 'if', and question words ('who', 'what', 'where', 'when', 'why', 'how').

When a noun clause functions as the subject, it often creates a complex sentence structure that can confuse readers. For example: 'What you said during the meeting surprised everyone.' Here, the entire clause 'What you said during the meeting' is the subject of the verb 'surprised'. When functioning as an object, a noun clause follows a verb: 'I know that she is arriving tomorrow.'

Embedded questions are a specific type of noun clause that is heavily tested. In an embedded question, the word order changes from question format (verb-subject) to statement format (subject-verb), and the auxiliary 'do/does/did' is dropped. For example, the direct question 'Where did he go?' becomes the embedded noun clause 'I wonder where he went.' Using question word order in an embedded clause (e.g., 'I wonder where did he go') is grammatically incorrect and will likely appear as a distractor option on the ECLT.

Clause Types & Conjunction Matrix Table

Clause Type Function in Sentence Common Introductory Words / Conjunctions Example

Defining Relative Identifies the noun (no commas) who, whom, which, that, whose The book that you gave me is fascinating.

Non-defining Relative Adds extra info (uses commas) who, whom, which, whose (NEVER that) Paris, which is the capital of France, is beautiful.

Adverbial (Time) Modifies verbs (tells when) when, while, since, before, after, until I will call you after I finish my work.

Adverbial (Reason) Tells why because, since, as Since we are early, let's get coffee.

Adverbial (Concession) Shows contrast although, even though, whereas, while Although he studied, he failed the test.

Noun (Subject) Acts as the subject what, that, whether, whoever What she wants is clear to everyone.

Noun (Object) Acts as the object that, if, whether, who, what, why I don't know whether he will come.

By breaking down these clause structures, you can confidently navigate the dense reading passages and identify subtle grammatical errors on the ECLT exam.