Incomplete Adverb Clauses untuk TOEFL: Marker, Reduced Clauses, dan Prepositional Phrases (+ Contoh)

Incomplete Adverb Clauses adalah salah satu topik kunci di bagian Structure and Written Expression TOEFL. Di sini, Anda diminta mengenali dan melengkapi anak kalimat keterangan (adverb clause) yang “kurang” unsur, memilih konjungsi (kata sambung) yang tepat, atau mengubahnya menjadi bentuk yang lebih ringkas (reduced clause) tanpa mengubah makna.

Adverb clause adalah anak kalimat yang diawali adverb clause marker (mis. when, while, if, because, since, although, even though, as, before, after, once, unless) dan kemudian diikuti subject + verb. Ia dapat hadir sebelum atau sesudah induk kalimat; jika diletakkan di depan, wajib ada koma sebelum induk kalimat.

Incomplete Adverb Clauses untuk TOEFL

Mengapa “Incomplete” di TOEFL?

1. Kata sambung (marker) hilang sehingga relasi makna antar klausa kabur (waktu, sebab, kontras, kondisi).

2. Unsur klausa kurang tepat (mis. because of dipakai seolah-olah konjungsi, atau despite diikuti klausa, bukan frasa).

3. Kesempatan untuk mereduksi (mengubah full adverb clause menjadi bentuk ringkas) dilewatkan, atau justru dilakukan pada struktur yang tidak bisa direduksi (contohnya klausa penyebab dengan because).

Peta Konsep: Adverb Clause vs. Reduced Clause vs. Prepositional Phrase

• Full adverb clause: marker + subject + verb

• Reduced adverb clause: marker + participle (V-ing/V-3) atau marker + adjective (hanya bila subjek induk = subjek anak).

• Prepositional phrase (padanan): preposition + noun/gerund phrase (mis. despite the rain, because of traffic, during the break) — sering mengungkap relasi makna yang sama tanpa subjek–verba.

Daftar Adverb Clause Markers (Fungsi & Contoh)

Tabel berikut merangkum marker, relasi makna, dan contoh. Contoh telah diparafrasa agar lebih kontekstual, tetapi makna dan fungsi tetap sama dengan sumber.

Catatan penting koma: bila adverb clause berada di depan, pasang koma sebelum induk kalimat; bila diletakkan sesudah induk kalimat, umumnya tanpa koma.

Reduced Adverb Clauses (Pemendekan Anak Kalimat Keterangan)

Prinsip Umum

Anda boleh “mereduksi” adverb clause hanya jika subjek pada induk kalimat sama dengan subjek pada anak kalimat. Dalam bentuk yang dipendekkan, anak kalimat tidak lagi memuat subjek–verba; yang tersisa biasanya marker + present participle (V-ing), marker + past participle (V-3), atau marker + adjective.

Contoh transformasi (parafrasa):

• Waktu (present participle)
  When the team was presenting the results, the audience stayed focused. →
  When presenting the results, the audience stayed focused.

• Kondisi (present participle)
  If you are driving at night, reduce your speed. →
  If driving at night, reduce your speed.

• Kontras (past participle/adjective)
  Although it had been repaired, the device malfunctioned. →
  Although repaired, the device malfunctioned.
  Although he was nervous, he spoke clearly. →
  Although nervous, he spoke clearly.

Konjungsi yang Boleh Direduksi

although, while, if, when, before, after, until.
Tidak boleh: because (klausanya tidak bisa dipendekkan menjadi because + V-ing / V-3 / adjective).

Tip cepat TOEFL: jika Anda melihat because lalu setelahnya bukan klausa lengkap (melainkan frasa), hampir pasti salah di bagian Structure.

Prepositional Phrases dengan Makna Setara

Materi menandai fokus ini—bahwa beberapa prepositional phrases dapat menyampaikan makna yang sama dengan adverb clause tertentu.

Berikut ringkasan padanan yang lazim di tes:

1) Kontras

• although / even though ⟶ despite / in spite of + noun/gerund

  • Although the rain was heavy, the match continued. →
    Despite the heavy rain, the match continued.

  • Struktur: despite / in spite of diikuti frasa (bukan klausa). Rujukan penggunaan & perbedaan bentuk dapat dilihat pada panduan British Council dan catatan gaya lainnya. Learn English+1Scribbr

2) Sebab

• because + clause ⟶ because of / due to + noun phrase

  • Because the road was closed, we took an alternative route. →
    Because of the road closure, we took an alternative route.

  • Kaidah bentuk: because = konjungsi pengantar klausa; because of = preposisi pengantar frasa. Cambridge Grammar membedakan keduanya secara eksplisit. Cambridge Dictionary+1

3) Waktu (durasi/saat)

• when / while + clause ⟶ during + noun

  • While the keynote was speaking, the hall fell silent. →
    During the keynote, the hall fell silent.

  • Nuansa makna: as/when/while memperkenalkan klausa yang berjalan bersamaan; during memperkenalkan nama peristiwa/rentang waktu. Cambridge Dictionary

Uji cepat: Bila setelah kata itu Anda dapat menaruh noun/gerund, besar kemungkinan itu preposisi (despite, in spite of, because of, during). Bila Anda butuh subject + verb, itu konjungsi (although, because, while/when).

Pola Soal TOEFL & Strategi Menjawab

Pola 1 — Mengisi Marker yang Hilang

Ciri: Ada celah sebelum subject + verb pada anak kalimat.
Strategi: Tentukan relasi makna: waktu (when, while, as, before, after, until), sebab (because, since), kontras (although, even though, while), kondisi (if, unless). Cocokkan dengan logika kalimat dan tanda koma. (Rujuk daftar marker).

Pola 2 — Memilih Bentuk Reduced Clause yang Tepat

Ciri: Dua klausa berturut-turut dengan subjek sama; salah satunya bisa dipendekkan.
Strategi: Periksa: (1) subjek sama, (2) jenis kata kerja, (3) marker yang boleh direduksi (tidak untuk because). Gunakan V-ing untuk aksi aktif; V-3 untuk pasif; atau adjective untuk keadaan.

Pola 3 — Menolak Bentuk Salah (Konjungsi vs Preposisi)

Ciri: Because of + klausa (salah), atau Despite + klausa (salah).
Strategi: Ingat: because + clause, because of + phrase; although + clause, despite/in spite of + phrase. (Lihat catatan Cambridge & British Council). Cambridge DictionaryLearn English

Contoh-Contoh Terapan (dengan Pembahasan Singkat)

A. Menentukan Marker

1. ___ the museum had closed early, we visited the library instead.
   Kunci: Since/Because → relasi sebab.

2. ___ the lab was noisy, the technician kept working.
   Kunci: Although/Even though → kontras (hasil tetap berjalan).

3. We wore masks ___ handling the chemicals.
   Kunci: when/while (waktu bersamaan) atau during + noun (during the handling process)—pilih sesuai struktur. Cambridge Dictionary

B. Konjungsi vs Preposisi

4. (✓) Because temperatures dropped sharply, classes were cancelled.
   (✗) Because of temperatures dropped sharply, … → because of harus diikuti frasa (Because of the sharp temperature drop, …). Cambridge Dictionary

5. (✓) Despite the late hour, the discussion continued.
   (✗) Despite it was late, … → setelah despite gunakan noun/gerund phrase. Learn English

C. Reduced Adverb Clauses

6. When the data were being processed, errors appeared. →
   Reduced: When being processed, the data showed errors.

7. Although it was broken, the sensor still transmitted signals. →
   Reduced: Although broken, the sensor still transmitted signals.

8. If you are taking the iBT next month, plan your practice schedule now. →
   Reduced: If taking the iBT next month, plan your practice schedule now.
   Catatan: Tidak ada reduksi untuk because (Because being tired… ✗).

Tabel Ringkas: Transformasi Umum

Posisi Adverb Clause & Tanda Baca

• Di depan induk kalimat → pasang koma.

• Di belakang induk kalimat → umumnya tanpa koma (kecuali kasus penekanan tertentu).
  Aturan ini juga selaras dengan pedoman penulisan akademik populer.

Kesalahan Umum yang Perlu Dihindari

1. Mencampur konjungsi–preposisi: because of + clause (salah), despite + clause (salah). Gunakan struktur yang tepat. Cambridge DictionaryLearn English

2. Mereduksi tanpa subjek yang sama: reduksi hanya sah bila subjek induk = subjek anak. Mt. San Antonio College

3. Memaksa reduksi pada because: hindari; gunakan because of jika ingin bentuk frasa.

4. Lupa koma saat adverb clause di awal kalimat.

5. Mengira while selalu waktu: while bisa bermakna kontras juga; lihat konteks kalimat.

Mini Latihan (5 Butir) + Pembahasan Ringkas

Petunjuk: Pilih jawaban benar atau lakukan perbaikan sesuai instruksi.

1. (Marker) ___ we increased the sample size, the results remained the same.
   Jawab: Although/Even though (kontras), bukan because.

2. (Konjungsi vs Preposisi) Because of the device was overheating, the test stopped.
   Perbaikan: Because the device was overheating… atau Because of the overheating… (frasa). Cambridge Dictionary

3. (Reduksi) When the participants were completing the survey, the moderator waited.
   Perbaikan: When completing the survey, the moderator waited. (subjek sama).

4. (Padanan Preposisional) Although the evidence was limited, the claim was accepted.
   Versi frasa: Despite the limited evidence, the claim was accepted. Learn English

5. (Koma) When the facility opened the team began testing.
   Perbaikan: When the facility opened, the team began testing.

Key Takeaways (5 Poin)

1. Struktur inti: adverb clause = marker + S + V. Jika di depan induk kalimat, wajib koma.

2. Marker = makna relasi: waktu (when/while/as), sebab (because/since), kontras (although/even though/while), kondisi (if/unless).

3. Reduced clause sah bila subjek sama; gunakan V-ing/V-3/Adj. Because-clause tidak bisa direduksi.

4. Prepositional phrase sebagai padanan: despite/in spite of (kontras), because of/due to (sebab), during (waktu–event). Gunakan frasa, bukan klausa. Learn EnglishCambridge Dictionary

5. Cek cepat TOEFL: (a) relasi makna → pilih marker, (b) struktur frasa vs klausa, (c) subjek sama untuk reduksi, (d) tanda koma.

TERKAIT: Incomplete Appositive: Panduan TOEFL Structure + Contoh & Strategi

Latihan Soal dan Pembahasa

A. Sentence Completion – Pilih Penanda (Marker) yang Tepat (10 soal)

1) ___ the lab had closed early, we collected the samples the next day.
A. During
B. Because
C. Although
D. Unless
Jawaban: B
Pembahasan: Relasi sebab → gunakan because + clause. During memerlukan frasa; although = kontras; unless = syarat negatif.

2) ___ the forecast looked terrible, the organizers did not cancel the trip.
A. Because
B. Since
C. Although
D. During
Jawaban: C
Pembahasan: Relasi kontras: kenyataan berlawanan dengan ekspektasi → although/even though + clause.

3) The students asked detailed questions ___ the lecture ended.
A. After
B. Unless
C. Although
D. Because
Jawaban: A
Pembahasan: Relasi waktu berurutan → after + clause.

4) ___ you need any help with the dataset, email the teaching assistant.
A. When
B. If
C. Since
D. While
Jawaban: B
Pembahasan: Relasi kondisi → if + clause.

5) She took notes ___ the professor explained the model.
A. while
B. because
C. unless
D. after
Jawaban: A
Pembahasan: Relasi waktu simultan → while/as/when + clause.

6) Some hypotheses are easy to test, ___ others require longitudinal data.
A. when
B. while
C. because
D. since
Jawaban: B
Pembahasan: while juga dapat bermakna kontras (“sementara yang lain…”).

7) The team waited ___ the ambulance arrived.
A. while
B. until
C. since
D. because of
Jawaban: B
Pembahasan: Relasi hingga suatu waktu → until + clause.

8) The first train pulled in ___ the second one pulled out.
A. as
B. while
C. since
D. although
Jawaban: A
Pembahasan: as menyatakan dua peristiwa terjadi bersamaan.

9) We can’t start the experiment ___ everyone is in the room.
A. unless
B. if
C. while
D. although
Jawaban: A
Pembahasan: unless = syarat negatif (“kecuali jika…”).

10) ___ the road was flooded, the driver decided to turn back.
A. During
B. Since
C. Due to
D. Despite
Jawaban: B
Pembahasan: since/because + clause untuk sebab. During dan despite memerlukan frasa; due to adalah preposisi (+ frasa), bukan konjungsi.

B. Conjunction vs Preposition – Bentuk Mana yang Benar? (5 soal)

11) Pilih kalimat yang benar.
A. Because the heavy traffic, we were late.
B. Because of the heavy traffic, we were late.
C. Because of the heavy traffic was bad, we were late.
D. Because of the heavy traffic, were we late.
Jawaban: B
Pembahasan: because of + noun phrase; because + clause. A salah (setelah because harus klausa), C salah (setelah because of tidak boleh klausa), D salah (inversi tak beralasan).

12) Pilih kalimat yang benar.
A. Although the rain, the match continued.
B. Despite it was raining, the match continued.
C. Although it was raining, the match continued.
D. Despite of the rain, the match continued.
Jawaban: C
Pembahasan: although + clause benar. Despite + NP/gerund (tanpa of). A salah (setelah although harus klausa), B salah (setelah despite bukan klausa), D salah (bentuk yang baku: despite the rain).

13) Pilih kalimat yang benar.
A. During the meeting was long, we left early.
B. While the meeting was long, we left early.
C. During the meeting lasted long, we left early.
D. While the meeting, we left early.
Jawaban: B
Pembahasan: while + clause (kondisi/keterangan). During diikuti frasa (mis. during the meeting), bukan klausa.

14) Pilih pelengkap yang tepat: “___ the malfunction, the test stopped.”
A. Because
B. Because of
C. Although
D. While
Jawaban: B
Pembahasan: Pola because of + NP cocok: Because of the malfunction…. Because butuh klausa.

15) Pilih kalimat yang benar.
A. In spite of the high price, many people bought it.
B. Even though the high price, many people bought it.
C. In spite the high price, many people bought it.
D. Even though of the high price, many people bought it.
Jawaban: A
Pembahasan: in spite of + NP benar. Even though + clause. C kurang of; D salah struktur.

C. Reduced Adverb Clauses – Pemendekan yang Tepat (5 soal)

16) Pilih revisi terbaik dengan reduced adverb clause (subjek sama).
Kalimat asli: When the engineers test the machine, they record the results.
A. When testing the machine, they record the results.
B. When tested the machine, they record the results.
C. When being test the machine, they record the results.
D. When to test the machine, they record the results.
Jawaban: A
Pembahasan: Subjek anak = subjek induk (the engineers/they), maka when + V-ing sah. B/C/D salah bentuk.

17) Pilih reduksi yang benar.
Kalimat asli: Although it was damaged, the device functioned.
A. Although damaging, the device functioned.
B. Although damaged, the device functioned.
C. Although being damaged, the device functioned.
D. Although to be damaged, the device functioned.
Jawaban: B
Pembahasan: Untuk keadaan pasif/adjektiva, gunakan Although + past participle/Adj → Although damaged….

18) Pilih reduksi yang benar.
Kalimat asli: If you are traveling with liquids, follow the rules.
A. If traveled with liquids, follow the rules.
B. If traveling with liquids, follow the rules.
C. If being travel with liquids, follow the rules.
D. If to travel with liquids, follow the rules.
Jawaban: B
Pembahasan: If + V-ing boleh bila subjek sama (you → understood). A salah tense/voice; C/D salah bentuk.

19) Pilih reduksi yang benar.
Kalimat asli: After he had finished the report, he submitted it.
A. After finishing the report, he submitted it.
B. After finished the report, he submitted it.
C. After to finish the report, he submitted it.
D. After having finish the report, he submitted it.
Jawaban: A
Pembahasan: After + V-ing (subjek sama) adalah bentuk ringkas paling alami. B salah bentuk; C infinitif; D salah participle.

20) Pilih kalimat yang benar.
A. Because being tired, he left early.
B. Because tired, he left early.
C. Because he was tired, he left early.
D. Because of being tired, he left early.
Jawaban: C
Pembahasan: because + clause. Klausa because tidak direduksi (Because being… ✗). Jika ingin bentuk frasa, gunakan because of + NP: Because of his fatigue, he left early (bukan because of being).