TOEFL iBT Readingの“Complete the Words”：品詞を手がかりに欠けた文字を補う方法

TOEFL iBTの“Complete the Words”では、いくつかの単語の最後の文字が欠けた短い段落を読み、その文字を補います。正しい単語にたどり着くための確認は三つです。印刷された文字をすべて残すこと、その単語が文の中で果たす役割（名詞、動詞、形容詞、副詞）を決めること、完成した文を読み直すことです。この記事は2026年に導入されたTOEFL iBTの形式に基づき、中級（B1）以上の英語力がある学習者に向けて書きました。

この記事が向いている人

2026年に導入されたTOEFL iBTの形式に向けて準備し、“Complete the Words”に初めて取り組む受験者。
段落の話題は理解できても語尾を間違える学習者。たとえば文に“carefully”が必要なのに“careful”と書いてしまう方。
文法とつづりも同時に鍛えられる、短い毎日の読解の習慣がほしい方。
まだ早い：“damage”、“replace”、“safe”のような日常語がまだなじみのない場合（A2程度）は、先に語彙を増やしてから戻ってきましょう。
簡単すぎる：練習用の段落を間違いなく完成できるなら、ほかの読解問題や文を組み立てる問題に進みましょう（下のリンク）。

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単語カード

Personal · reading habits

When you read in English, do you usually guess unknown words quickly or stop and check them? Has a guess ever caused a problem?

Useful: ‘I tend to…, which means that…’ · ‘Once I guessed…, and it turned out…’ · ‘These days I try to…’

Personal · exam strategy

In a timed reading test, is it better for you to read faster or more carefully? Why?

Useful: ‘For me, the bigger risk is…’ · ‘It depends on the type of question.’ · ‘If I read too quickly, I…’

会話の例

How do you choose the right form of a word?

Look at the job the word does in its sentence: noun, verb, adjective or adverb.

The examples on this page are teaching models. Later pages use different texts.

文の形

How do you choose the right form of a word?

Look at the job the word does in its sentence: noun, verb, adjective or adverb.

The examples on this page are teaching models. Later pages use different texts.

追加の練習

See how word forms change

Two adult learners discuss a reading task at a community study table.

A college team prepares old chairs for a community classroom. The chairs are damaged, but their wooden frames can be repaired. Volunteers follow an instruction card and work carefully, checking each joint before they paint it. A supervisor explains how to use the workshop safely. Some reusable materials come from earlier projects, while broken parts need a replacement. The team records what it has done so that a future group can understand the process and continue the work confidently.

How do you choose the right form of a word?

Look at the job the word does in its sentence: noun, verb, adjective or adverb.

The examples on this page are teaching models. Later pages use different texts.

Six forms in complete contexts

damage → damaged: The chairs are damaged. The -ed form describes their condition.
instruct → instruction: An instruction card tells workers what to do. The noun names guidance.
careful → carefully: Volunteers work carefully. The adverb tells us how they work.
safe → safely: Use the workshop safely. The adverb describes the manner of using it.
reuse → reusable: Reusable materials can be used again. The adjective describes the materials.
replace → replacement: A broken part needs a replacement. The noun names the new part.

Worked reconstruction

Volunteers work care_____. → carefully: five missing letters, fully, create an adverb.
The chairs are dam____. → damaged: four missing letters, aged, describe their condition.
An instruc____ card gives guidance. → instruction: four missing letters, tion, complete the noun.

Practise with visible choices

The college workshop gives old furniture a second life. Several [1] work___ prepare chairs for painting. One person sands the wood [2] care_____, while another checks that each surface is [3] sm____. Two [4] instruct___ explain the safety rules before anyone uses a machine. The group plans to [5] re___ the finished chairs in a student meeting room, saving money for other projects.

1
Gap 1: add only the missing letters to complete the word in the paragraph.
Several work______ prepare chairs for painting.
答えと解説を見る
ers
Several requires a plural count noun; workers names the people doing the task.
2
Gap 2: add only the missing letters to complete the word in the paragraph.
One person sands the wood care______,
答えと解説を見る
fully
Carefully is an adverb describing how the person sands the wood; caretaker is a noun and careering is a verb form meaning moving fast.
3
Gap 3: add only the missing letters to complete the word in the paragraph.
Each surface is sm______.
答えと解説を見る
ooth
Is smooth needs an adjective describing a surface without rough parts; smears and smells are noun or verb forms that cannot follow is here.
4
Gap 4: add only the missing letters to complete the word in the paragraph.
Two instruct______ explain the safety rules before anyone uses a machine.
答えと解説を見る
ors
Two needs a plural noun for people: instructors explain the rules. Instructing is a verb form and instructive is an adjective.
5
Gap 5: add only the missing letters to complete the word in the paragraph.
The group plans to re______ the finished chairs in a meeting room.
答えと解説を見る
use
Plans to needs a base verb that can take the chairs as its object: reuse means use them again. Reads is not a base form, and reply needs to before an object.

Complete a new paragraph without choices

A student club holds a repair event where neighbours bring items that no longer work properly. Before the event, volunteers [1] arran__ the tables by activity and place clear signs near the entrance. Each [2] visi___ describes the problem to a student, who [3] wri___ a short note. A trained helper [4] exa_____ the item and explains whether it can be repaired safely. Some repairs are [5] simp__, but others need [6] spec___ equipment. Visitors can watch and ask [7] ques_____ while the helper works. The club keeps useful materials for [8] fut___ events and [9] rec_____ what cannot be used. This [10] appro___ reduces waste and helps people learn practical skills.

Review the evidence and explain your decisions

A student club holds a repair event where neighbours bring items that no longer work properly. Before the event, volunteers arrange the tables by activity and place clear signs near the entrance. Each visitor describes the problem to a student, who writes a short note. A trained helper examines the item and explains whether it can be repaired safely. Some repairs are simple, but others need special equipment. Visitors can watch and ask questions while the helper works. The club keeps useful materials for future events and recycles what cannot be used. This approach reduces waste and helps people learn practical skills.

Discuss the reasoning

Choose two restored words and explain what the letters, grammar or context told you.
Paraphrase the paragraph for someone who has not read it.
Describe one error or uncertainty and the check that would help next time.

Check a rebuilt word three ways

A language café uses a calendar to coordinate its evening groups. One group discusses books, while another practises conversation about travel. The coordinator posts an update whenever a meeting moves to a different room. Members read the whole notice because the first sentence may explain the change and the final sentence may give a reason. A familiar word can still have the wrong form in a particular sentence. Good readers check the surviving letters, the surrounding grammar and the meaning of the whole message.

How do you check a word you have rebuilt?

Check the letters first, then the grammar, and then the meaning of the whole sentence.

The examples on this page are teaching models. Later pages use different texts.

Three checks on a possible answer

Check the letters: coordina___ → coordinator. The surviving prefix stays unchanged; add tor.
Check the grammar: one group discu____ books → discusses. A singular group takes the finite verb discusses.
Check the meaning: a meeting moves to a diff_____ room → different. The new room is not the same room; add erent.

Read again after reconstruction

Use the intact final sentence to confirm what the paragraph is trying to say.
Read every restored word inside its full sentence.
Mark the cue that settled a difficult choice, not only whether your answer was right.

Practise with visible choices

An evening reading group meets in a shared room above a local café. The [1] organis__ checks the room calendar every Monday. Members receive a [2] rem_____ before each meeting, and anyone bringing a guest must [3] not___ the group. If the café changes its closing time, the group [4] adj____ its schedule. A short message keeps everyone [5] in______ without requiring a separate phone call.

1
Gap 1: add only the missing letters to complete the word in the paragraph.
The organis______ checks the room calendar every Monday.
答えと解説を見る
er
The organiser is the person managing the group; organised is an adjective and organising is an -ing form. The printed prefix uses s, so keep it.
2
Gap 2: add only the missing letters to complete the word in the paragraph.
Members receive a rem______ before each meeting.
答えと解説を見る
inder
A reminder is a message that helps somebody remember; reminded and reminding are verb forms.
3
Gap 3: add only the missing letters to complete the word in the paragraph.
Anyone bringing a guest must not______ the group.
答えと解説を見る
ify
Must takes a base verb: notify means tell the group officially. Noting is an -ing form and notion is a noun.
4
Gap 4: add only the missing letters to complete the word in the paragraph.
The group adj______ its schedule.
答えと解説を見る
usts
The group is a singular subject, so adjusts (changes slightly) is the present-tense verb. Adjourn does not agree with a singular subject, and adjoins means is next to.
5
Gap 5: add only the missing letters to complete the word in the paragraph.
A short message keeps everyone in______.
答えと解説を見る
formed
Keeps everyone informed means everyone has the latest information; informer is a noun and intended does not fit after keeps everyone.

Complete a new paragraph without choices

The campus library has introduced a booking service for quiet study rooms. Students can [1] rese___ a room through the library website by choosing a date and a [2] sta_____ time. Each booking [3] la___ one hour, and a confirmation message is sent [4] auto_________. The message [5] inc_____ the room number and a link for making changes. Students who no longer need a room should [6] can___ the booking so someone else can use it. During busy weeks, staff may [7] lim__ how many bookings one student can make. These rules keep the [8] sys___ fair and make shared [9] spa___ more [10] acce______ to everyone.

Review the evidence and explain your decisions

The campus library has introduced a booking service for quiet study rooms. Students can reserve a room through the library website by choosing a date and a starting time. Each booking lasts one hour, and a confirmation message is sent automatically. The message includes the room number and a link for making changes. Students who no longer need a room should cancel the booking so someone else can use it. During busy weeks, staff may limit how many bookings one student can make. These rules keep the system fair and make shared spaces more accessible to everyone.

Discuss the reasoning

Choose two restored words and explain what the letters, grammar or context told you.
Paraphrase the paragraph for someone who has not read it.
Describe one error or uncertainty and the check that would help next time.

Word forms in the passage

1
Choose the words that complete the sentence from the passage.
The message spread quickly, partly because readers could decode it without much ______.
答えと解説を見る
difficulty
After much, we need an uncountable noun: much difficulty.
2
Choose the words that complete the sentence from the passage.
Its popularity nevertheless raises a ______ question for psychologists
答えと解説を見る
genuine
Between the article a and the noun question, we need an adjective.
3
Choose the words that complete the sentence from the passage.
These pauses, or fixations, ______ last about a quarter of a second.
答えと解説を見る
typically
An adverb modifies the verb last; the sentence already has a subject and a verb.
4
Choose the words that complete the sentence from the passage.
Surprisingly, they are more ______ when the letter appears inside a real word
答えと解説を見る
accurate
After the verb be (are more), we need an adjective to describe the subject they.
5
Choose the words that complete the sentence from the passage.
This finding suggests that ______ is not a simple left-to-right process of adding letters together.
答えと解説を見る
recognition
The that-clause needs a subject before is, so the gap needs a noun.
6
Choose the words that complete the sentence from the passage.
When researchers scrambled longer words, or moved letters far from their original positions, reading slowed ______ and errors increased.
答えと解説を見る
considerably
An adverb describes how much the verb slowed changed.
7
Choose the words that complete the sentence from the passage.
Second-language readers usually have less of that background knowledge, so a confident guess is more ______.
答えと解説を見る
risky
After is more, we need an adjective (more risky) to describe the noun guess.
8
Choose the words that complete the sentence from the passage.
Skilled reading really does ______ on expectation
答えと解説を見る
depend
Emphatic does is followed by the base form of the verb: does depend, not does depends.

この単元を学ぶ

どの方法で学びますか？

アカウントをお持ちですか？

無料アカウントで1つの単元をずっと開いておけます。

どんな問題か

一部の単語が途中までしか印刷されていない短い段落が出ます。前半はあり、残りが欠けています。段落が正しく読めるように、それぞれの単語を完成させるのが課題です。たいていの場合、印刷された文字と文の両方に合う答えは一つだけです。

ここでの練習例では、下線一つが1文字を表すので、空欄から語尾の長さもわかります。古いいすを修理するボランティアについての段落から、解き方の例を三つ紹介します。

“Volunteers work care_____.” → carefully：5文字の“fully”で副詞になります。文が、どのように作業するかを述べているからです。
“The chairs are dam____.” → damaged：4文字の“aged”で、いすの状態を表します。
“The card gives an instruc____.” → instruction：4文字の“tion”が、“an”のあとの名詞を完成させます。

空欄ごとの確認

話題を知っていれば答えに近づけますが、形を決めるのは文です。段落全体を意味をつかむために一度読み、それから空欄ごとに確認しましょう。

印刷された文字を残す：答えはその文字に付け足すもので、置き換えるものではありません。
単語の役割を決める：“a”、“the”や形容詞のあとは名詞、“can”、“should”、“to”のあとは動詞の原形、名詞の前や“is”のあとは形容詞、どのように起こるかを表すなら副詞です。
空欄の数を数える：意味が合っていても長さが違えば、それは違う単語です。
完成した文を読む：不自然に聞こえたら、語尾をもう一度確かめます。

解いてみよう：“work___”を完成させる語尾は？

短い質問と答えを聞き、そこで挙げられている確認を、同じ段落の別の文に使ってみましょう。語尾の候補は三つですが、合うのは一つだけです。

“Several work___ prepare chairs for painting.”

Question How do you choose the right form of a word?

Answer Look at the job the word does in its sentence: noun, verb, adjective or adverb.

“Several work___”を完成させる語尾はどれですか？

覚えておきたい語尾

多くの空欄には、品詞を変える語尾が隠れています。語尾は単語だけでなく、例文と一緒に覚えましょう。

-lyは形容詞を副詞にします：careful → carefully、safe → safely。
-tionと-mentは名詞を作ります：instruct → instruction、replace → replacement。
-edはよく状態を表します：damage → damaged。
-ableは形容詞を作ります：reuse → reusable（“Reusable materials can be used again.”）。
-erは何かをする人を表します：work → worker、“several”のあとならworkers。
複数形と動詞の-s：“each worker”だが“several workers”、“a helper checks”だが“helpers check”。

自分に合った方法でこの単元を学ぶ

練習のしかた

1日に段落一つで、習慣を作るには十分です。この手順は約15分かかります。

読む：書かずに段落全体を一度読みます。
補う：欠けた文字だけを書きます。難しい空欄は飛ばして、あとで戻ります。
確かめる：答えを見る前に、完成した文をすべて読み直します。
説明する：答え二つについて、決め手になった手がかりを書きます。文字のパターン、文法のルール、意味のどれでしたか。
集める：間違えた語尾を、care、careful、carefully、carelessのような語のファミリーのリストに加えます。

よくある間違い

答えを落とす原因の多くは、知らない単語ではなく形です。日本語では「いす二つ」のように数のあとでも名詞に複数の印を付けず、冠詞もないため、“two chair”や“several worker”のような間違いが起こりやすくなります。“several”、“two”、“a”のあとの名詞はすべて確認しましょう。

単語全体を書く、または印刷された文字を変えてしまう。
話題には合うが文法に合わない単語を選ぶ：文に“carefully”が必要なのに“careful”。
“several”、“many”、“two”のあとで複数形を忘れる。
空欄の数を無視する。
語尾のつづりを間違える：“carefuly”、“instrucsion”。

次のステップ

練習用の段落を完成させ、答えを二つ説明できるようになったら、お知らせやメッセージ、より長い文章を読んで情報を組み合わせる問題に進みましょう。ライティングセクションの文を組み立てる問題も、同じ品詞の確認を使います。

よくある質問

TOEFL iBTの“Complete the Words”とは何ですか？

2026年に導入されたTOEFL iBTの形式にあるReadingの問題です。短い段落の中で、いくつかの単語の欠けた最後の文字を補い、段落が正しく読めるようにします。

単語全体を書きますか、それとも欠けた文字だけですか？

欠けた文字だけです。印刷された前半はそのまま残し、あなたが書く文字で単語を完成させます。

TOEFLの“Complete the Words”を上達させるには？

毎日短い段落を一つ練習し、完成した文をすべて読み直して、答え二つの手がかりを書き出しましょう。単語を一つずつではなく、care、careful、carefullyのような語のファミリーで覚えましょう。

TOEFL iBT Readingの練習にはどのくらいのレベルが必要ですか？

練習の効果が最も出やすいのは中級（B1）程度からです。それより下では段落の単語の多くが初めて見るもので、問題が当て推量になってしまうので、先に語彙を増やしましょう。

次の練習を探す

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TOEFL iBT Readingの“Complete the Words”：品詞を手がかりに欠けた文字を補う方法

この記事が向いている人

サンプルページを開く

単語カード

会話の例

文の形

追加の練習

See how word forms change

Practise with visible choices

Complete a new paragraph without choices

Review the evidence and explain your decisions

Check a rebuilt word three ways

Practise with visible choices

Complete a new paragraph without choices

Review the evidence and explain your decisions

Word forms in the passage

どんな問題か

空欄ごとの確認

解いてみよう：“work___”を完成させる語尾は？

覚えておきたい語尾

練習のしかた

よくある間違い

次のステップ

よくある質問

次の練習を探す

次は何をしましょうか？

Flaiで練習を続けよう

ライブの先生と学ぶ