There are five types of subordinate clauses in English: the subject, the predicative, the attributive, the object and several types of adverbial clauses.
Adverbials happen to be the thing this challenge is about.
Create a correct sentence.
So full was the train that commuters had to stand all the way.
Starting a sentence with So full creates an adverbial clause of result. Using so+adjective means you invert the position of verb and subject: So full was the train. The second part of the sentence is the independent clause and follows the normal word order ... commuters had to stand all the way
The students work hard. Why?
Choose the correct order.
The students do their work well to make sure the teacher is happy.
The students do their work well to make sure the teacher is happy.
To make sure the teacher is happy is the subordinate clause, and an adverbial clause of reason. This is the answer to a why question. The students do their work well is the independent main clause. To make sure links the two clauses.
- Correct. Even though links the two sentences and creates an adverbial of concession.
- Incorrect. There are two independent clauses here that are not linked in any way. The comma is not enough to indicate a relationship - there is information missing. Even if you read the two as seperate sentences, it has stopped making sense (if he was so careful, why was his knee sore?).
- The sentence starts with although..., creating the adverbial (subordinate) clause of concession. The comma separates from the ordinary clause that it relates to: his knee was really sore after the performance.
- Very careful had been the dancer has incorrect word order; the dancer is the subject and it should go before the verbs had been and adjective very careful. It also misses a link between the two sentences, so this is incorrect in many ways.
- Correct. It gives a reason.
- Incorrect. It does not refer to time.
- Incorrect. It is a dependent or subordinate clause as you cannot use it by itself.
- Correct. You have to insert a comma between the two parts.
My suit is pink-and-blue. I was at a party.
Choose the correct order.
I went to the party wearing a pink-and-blue suit.
I went to the party wearing a pink-and-blue suit.
I went to the party is the independent main clause. It follows normal word order (Subject/Verb/Object). wearing a pink-and-blue suit says something about HOW I went to the party, and functions as an adverbial. pink-and-blue is an adjective, and comes before suit.
- Correct! After I insulted him is an adverbial clause of reason.
- Incorrect. After I insulted him is the dependent clause. After that, normal word-order applies: Subject/Verb(s)/Object: The waiter/would not serve/me.
- Incorrect - This is a dependent clause with who, and can form the subject of a full sentence: The waiter who would not serve me after I insulted him went home early that day. (Compare to: He went home early that day.)
- Correct! You can put the adverbial at the start of the sentence or at the end. After I insulted him...
- Comparing two parts: Which part of the church is oldest? Here it means that the rest of the church is oldest. Older than the tower is the rest of the church. If you want to say the tower is oldest, use The tower is older than the rest of the church.
- Correct! The chilli is so hot (independent clause) / that it feels like my mouth is on fire (dependent clause) - it functions as an adverbial clause of comparison.
- Incorrect: It looks as if the doctor cannot help the patient. It is an adverbial clause of comparison. The word order is incorrect.
- Incorrect - this is a simple sentence. The capital city of the United Kingdom is an adverb of place, it is not a clause (it has no verbs).
- Correct! Wherever they were sent is a dependent clause, it cannot stand on its own. It is an adverbial clause of place.
- Incorrect - this is a simple sentence. London is an adverb of place.
We submitted our proposal on time. They did not look at it.
Choose the correct order.
Our proposal was not considered although we submitted it on time.
Our proposal was not considered although we submitted it on time.
The second part although we submitted it on time is a clause of concession. Both parts use standard word order.
Select the order.
Little did he know that his girlfriend was going to propose at the top of the tower that evening.
Little did he know that his girlfriend was going to propose at the top of the tower that evening.
Sentences starting with little take inverted word order, where the first verb comes before the subject (Little did he know). The dependent clause takes normal word order Subject/Verb/ObjectPlace/ObjectTime: his girlfriend/ was going to propose/at the top of the tower/that evening.
Phrase
- the red car — noun phrase (functions as one noun unit)
- on the table — prepositional phrase
- has been running — verb phrase
- very quickly — adverb phrase
A phrase is a group of words that functions as a single unit WITHOUT a subject + verb pair. Types: noun phrase, verb phrase, prepositional phrase, adjective phrase, adverb phrase.
Key distinction: a phrase lacks a subject-verb pair. If it has subject + verb → it's a clause, not a phrase. Phrases are the building blocks clauses are made of.
Adverb
- ✅ She sings beautifully — ❌ She sings beautiful
- ✅ He drives carefully — ❌ He drives careful
- ✅ They arrived late — ✅ a late train (same form, both roles)
- ✅ She works hard — ❌ She works hardly (different meaning!)
The -ly words are adverbs — they modify verbs, adjectives, or other adverbs, telling you how, when, where, or to what degree.
Pattern: most adjectives become adverbs by adding -ly, but watch the exceptions — fast, hard, late, well — that keep the same shape or change meaning entirely.
Dependent clause
- ❌ Because I was tired. — fragment (dependent clause standing alone)
- ✅ I left early because I was tired. — attached to independent clause
- ✅ The man who called is my uncle. — relative clause (modifies man)
- ✅ If you're ready, let's go. — conditional dependent clause
A dependent clause has a subject + verb but cannot be a complete sentence. It starts with a subordinating word (because, if, when, although, who, which) and must attach to an independent clause.
Test: does the clause start with a subordinator and feel incomplete on its own? → dependent clause. On its own, it's a fragment — attach it to a main clause.
Complex sentence
- ✅ Because I overslept, I missed the bus. — dependent clause (reason) + independent
- ✅ The man who called is my uncle. — relative clause inside the sentence
- ✅ If it rains, we'll stay inside. — conditional dependent + independent
- ❌ Because I overslept. — fragment (dependent clause alone)
A complex sentence pairs an independent clause with one or more dependent clauses linked by subordinating conjunctions (because, although, if, when) or relative pronouns (who, which, that).
Pattern: independent clause = the main point. Dependent clause = the background, reason, or condition. Move the dependent clause around for emphasis.
Clause
- I missed the bus. — ✅ independent clause (stands alone)
- Because I overslept. — ❌ fragment (dependent clause, can't stand alone)
- Because I overslept, I missed the bus. — ✅ dependent + independent = complete sentence
- I missed the bus, and I was late. — ✅ two independent clauses joined by and
A clause is a unit built around a verb with a subject. Independent = can stand alone. Dependent = needs an independent clause to complete it.
Test: does the group of words have a subject + verb AND can it be a sentence on its own? Yes → independent clause. Has a subject + verb but feels incomplete → dependent clause.
B1 | Intermediate
- ✅ If I had more time, I would travel more. — second conditional
- ✅ The bridge was built in 1920. — passive voice
- ✅ She said she was tired. — reported speech with backshift
- ✅ Although it rained, we enjoyed the trip. — complex sentence with concession
These are B1 patterns — the CEFR intermediate level. At B1 you link ideas, use passive voice, handle reported speech, and manage second conditional — enough for travel, work basics, and everyday independence.
Marker: if you can explain why something happened and follow a news story, you're B1.
Medium
- If I were you, I would apologise. — one rule (second conditional), but distractors like was tempt you
- Answers require active thought, not instant pattern recognition
- Vocabulary and context are realistic, not artificially simplified
- Usually tests one rule, but the wrong answers are plausible
Medium marks middle-difficulty challenges: A2–B1, one rule tested, but with realistic distractors that require genuine understanding.
Use "Medium" when Easy feels too obvious but Hard feels overwhelming. This is where most productive learning happens — the sweet spot of difficulty.