What you'll learn
By the end of this lesson, you'll be able to build complex sentences with subordinate clauses of reason, contrast, time and condition.
When do I use it?
A subordinate clause depends on the main clause and is introduced by a conjunction:
- Reason: because, since, as: "We stayed home because it was raining."
- Contrast: although, even though, whereas: "She is rich, whereas her brother is poor."
- Time: while, before, after, as soon as: "Call me as soon as you arrive."
- Condition: unless, provided that, even if: "Even if it rains, we'll go."
Subordinate clauses can come first (with a comma) or after the main clause (no comma needed).
How do I form it?
conjunction + subject + verb (subordinate), + main clause main clause + conjunction + subject + verb
- Although the task was hard, we enjoyed it.
- We left early because the traffic was heavy.
- While I understand your point, I disagree.
- I'll come unless something urgent comes up.
Common mistakes for Spanish speakers
Spanish often uses two main clauses joined by "y" or "pero" where English prefers a subordinator; also the "doble negación" pattern: "a menos que no" is wrong in English — "unless" already means "if not". Do not double conjunctions ("although... but" is wrong, like "aunque... pero"). And watch the word order: the subject stays before the verb in the subordinate clause — never "although did I understand".
One subordinator per pair: although (not but), unless (not unless not), because (not because why).
Practice
Multiple Choice
C1Which sentence is correct?
Fill in the Blank
C1I'll help you it conflicts with my schedule.
Hint: 'Unless' = if not.
Find the Error
C1Sentence Transformation
C1Task: Rewrite with 'since' instead of 'because'
Hint: 'Since' works like 'because' for reasons.
Practice Speaking
Apply what you've learned in a real conversation with AI feedback.
Level: C1