What Is a Complex Sentence?
A complex sentence is composed of one independent clause, very similar to a simple sentence, and one dependent clause that adds information to the first one but couldn’t exist without it. Both clauses have a subject and a verb and may have other elements as well. However, dependent clauses are often introduced by subordinating conjunctions, such as time conjunctions (when, whenever, before, after, until, while, since, etc.), location conjunctions (where, wherever), and cause-and-effect conjunctions (as, although, because, provided that, once, etc.).
We highlighted the independent clause in red to make things easier for you.
Keep in mind that two independent clauses don’t make a complex sentence, but a compound sentence. For instance, “I love rugby, and you like hockey.” Is a compound sentence, not a complex one. “I loved rugby until you introduced me to hockey.” is a complex sentence.
Examples of Complex Sentences in the Present Simple Tense
1. I feel happy whenever I hear you.
2. I am energetic because I slept well.
3. I don't get it, so maybe you can explain it to me again.
4. I travel whenever I have the time.
5. It's not a big deal once you understand the algorithm.
6. Can you spell that out for me because English is not my first language?
7. Could you give me more time to figure this task out, provided that I finish the project before the deadline?
8. Can I get you a sandwich when it's lunchtime?
9. I want to see the timeline, if you don't mind.
10. I am very interested, as you can see.
Examples of Simple Sentences in the Present Continuous Tense
11. I am working on my tasks while my colleague is having a coffee.
12. They are travelling to Rome as we speak.
13. After the sun sets, we are all going home.
14. I am walking to the next meeting, provided that it doesn't rain.
15. She is waiting for me at the cafe until the meeting is over.
Examples of Simple Sentences in the Present Perfect Tense
16. I have done my tasks, whereas my colleague has had his coffee.
17. You have spoken at the meeting although you were nervous.
18. While my boss consulted the Gantt chart, I have come up with a new idea.
19. He has studied English since he was 12.
20. She has taken the bus to work since the flexible schedule was implemented.
21. I have finished my task as early as I could.
22. The office has closed before we could get there.
23. I've reordered the files because I couldn't stand the mess.
24. They have had lunch while the rest of us were in the meeting.
25. We have taken the train because the plane was too expensive.
Examples of Simple Sentences in the Present Perfect Continuous Tense
26. I have been working on these files since the day you hired me.
27. Thomas have been thinking I can't do this because I didn't study engineering.
28. Although I work hard, I haven't been saving enough money.
29. Since you were in the meeting, she has been cleaning the offices.
30. Jacob has been feeling sick since you had that meeting in the morning.
Examples of Simple Sentences in the Past Simple Tense
31. I drove to work because my schedule allowed it.
32. She traveled around the world after she finished her studies.
33. We ate at that big restaurant because the company paid the bill.
34. I wanted a better work-life balance because I missed my kids.
35. Tom stayed awake all night so he could finish the project on time.
36. The manager asked for overtime provided that the contract would be signed.
37. Before he left the office, he wrote me a note.
38. After he came back from his leave, he started working on the promotions.
39. Although she was nervous, she performed well.
40. Sarah took the bus to work after she sold her car.
Examples of Simple Sentences in the Past Continuous Tense
41. I was minding my business when the door slammed open.
42. He was writing at his desk when the boss came in.
43. Maria was working on the new task because no one else did.
44. Tom was seeking a new job after he found out he would be laid off.
45. I was waiting for you as we agreed.
Examples of Simple Sentences in the Past Perfect Tense
46. I had done my part once I knew how close the deadline was.
47. He had finished the project before the new requirements arrived.
48. Although the deadline was close, she had taken a few days off.
49. By the time I left work, I had proven my point.
50. The team had recommended a new approach because the old one wasn't working.
51. Internet had become the new normal, although not many people thought so in the beginning.
52. The renovations had been completed before we moved in.
53. Andrew had had his time off before we signed this contract.
54. She had joined us before the last session of the conference started.
55. I had spent too much money although I didn't have it.
Examples of Simple Sentences in the Future Simple Tense
56. I will spend too much money although I don't have it.
57. Ben will wait in the library until you finish the meeting.
58. She will clean the office although you are working at your desk.
59. Wherever Alexandra find an interesting event, she will make plans to attend.
60. I will not buy more work clothes because I work from home now.
61. She will travel the world once she finishes her degree.
62. If he gets the promotion, he will buy a new car.
63. He will be at the meeting, provided that he is invited.
64. We will move the meeting inside as soon as the rain starts.
65. You will be exhausted if you don't take any breaks.
Examples of Simple Sentences in the Future Continuous Tense
66. You will be eating at your desk if you don't finish on time.
67. Although she left home early, she will be arriving at the office late.
68. Anna will be dining with clients whenever she manages to get an appointment.
69. You will be enjoying the promotion provided that you work overtime.
70. I will already be working by the time you arrive at the office.
Examples of Simple Sentences in the Future Perfect Tense
71. I will have felt the same way by the meeting we have tomorrow.
72. You will have left the room before they start talking.
73. Sarah will have enjoyed her lunch by the time the afternoon meeting starts.
74. You will have appreciated the networking before the event begins.
75. They won't have saved enough money by the time they decide to quit their jobs.
76. By the time we agree on the project, he will have signed the contract.
77. I will have made up my mind before the conference starts.
78. You will not have met me before the new office opens.
79. You will have been late by the time you decide to take the car.
80. Will I catch the bus if I arrive at 5 AM?
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Related: 100 Simple sentences.
10 Types of Nouns.