# TOEFL Word Families: Spelling and Ending Drills | topin

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## Use four constraints before choosing the ending

ETS’s current Reading page describes completing partially missing words in context. Its specifications connect the task with vocabulary, word order and comprehension. The official sample shows letter gaps and provides missing-letter answers. Use the entire sentence and visible prefix rather than choosing a word simply because it belongs to the passage topic.

The British Council’s word-building guidance explains that suffixes can suggest word class: forms ending in -ment, -ion or -ness often function as nouns, while endings such as -ive and -al often occur in adjectives. These are clues, not an automatic recipe. You still need to know the actual word and its correct spelling.

__Our four-constraint check for a practice gap.__
| Constraint          | Question                             | Example                                               |
| ------------------- | ------------------------------------ | ----------------------------------------------------- |
| Meaning             | Does the word fit the situation?     | A study can measure a change                          |
| Grammar             | Which word class and inflection fit? | A change may need a noun or plural noun               |
| Visible letters     | Does the candidate begin correctly?  | measure and pressure cannot share an arbitrary prefix |
| Length and spelling | Does the exact form fit the spaces?  | measurement differs from measurements                 |

Read the intact opening sentence and the sentence around the gap. Decide whether the gap needs a verb, noun, modifier or function word. Then narrow the family and check the shown letters. If two candidates fit the meaning, grammar and length can resolve the choice.

For the basic task mechanics, see [Complete the Words](/toefl/reading/complete-the-words). This article extends the preparation into word-family production and error diagnosis rather than repeating the introductory worked paragraph.

## Build a small family table from words you actually miss

Start with recurring errors from fresh Reading and Writing practice. Record a base form, a related noun, a related adjective where available and one contextual sentence. Do not assume every family has a useful form in every column. Blank or absent forms are better than invented words.

__Original selection of common families; these are study examples, not an ETS vocabulary list.__
| Base or related verb | Noun        | Adjective     | Adverb                    |
| -------------------- | ----------- | ------------- | ------------------------- |
| analyse              | analysis    | analytical    | analytically              |
| decide               | decision    | decisive      | decisively                |
| vary                 | variation   | variable      | variably                  |
| respond              | response    | responsive    | responsively              |
| create               | creation    | creative      | creatively                |
| depend               | dependence  | dependent     | dependently               |
| compare              | comparison  | comparative   | comparatively             |
| observe              | observation | observational | Not needed for this drill |

The point is not to memorise all four columns at equal frequency. Learn the form needed for the sentence and notice spelling changes between forms. Analysis and analyse share meaning but cannot be exchanged in every grammatical slot. An adjective followed by a noun needs a different form from a noun following an article.

Use a dictionary to verify a questionable form before adding it to your record. Some theoretically available adverbs are uncommon or awkward in a particular sentence. Producing a real word is not sufficient if its use fails the context.

If your preparation material uses American spelling, follow the visible letters and available spaces in that task. Our copy uses British English, but you should not replace a shown American prefix with your preferred spelling. The specific input pattern is a constraint on the missing letters.

## Twelve original ending drills with grammatical explanations

Original practice instructions: complete the whole word from the visible letters and underscores, then record only the missing letters as the input. Each underscore below is one letter. These are single-sentence drills, not a replica of the official every-second-word paragraph pattern. Attempt the set before checking the answers.

__Twelve original spelling drills; whole-word answers are shown for review.__
| Item and sentence                                                      | Whole word   | Missing letters and reason          |
| ---------------------------------------------------------------------- | ------------ | ----------------------------------- |
| 1\. The team compared two possible solu\_\_\_\_\_ to the problem.      | solutions    | tions; plural noun after two        |
| 2\. The results were reported accu\_\_\_\_\_\_ in the summary.         | accurately   | rately; adverb describing reported  |
| 3\. A clear expla\_\_\_\_\_\_ helped readers follow the method.        | explanation  | nation; singular noun after a clear |
| 4\. The findings depend on careful obser\_\_\_\_\_\_ of the samples.   | observation  | vation; noun after careful          |
| 5\. The class examined the rela\_\_\_\_\_\_\_\_ between the two ideas. | relationship | tionship; noun after the            |
| 6\. The tutor asked for a brief compa\_\_\_\_\_ of the options.        | comparison   | rison; noun after a brief           |
| 7\. The new process was more effi\_\_\_\_\_ than the earlier one.      | efficient    | cient; adjective in a comparison    |
| 8\. Several vari\_\_\_\_\_\_ were recorded during the experiment.      | variations   | ations; plural noun after several   |
| 9\. The reviewer responded consis\_\_\_\_\_\_ to similar requests.     | consistently | tently; adverb describing responded |
| 10\. The students discussed the limita\_\_\_\_\_ of the method.        | limitations  | tions; plural noun in this context  |
| 11\. The proposed design is pract\_\_\_\_ for a small room.            | practical    | ical; adjective after is            |
| 12\. The team needs reli\_\_\_\_ equipment for the project.            | reliable     | able; adjective before equipment    |

Items 1, 8 and 10 require plural forms in their displayed contexts. Items 2 and 9 require adverbs. Items 7, 11 and 12 need adjectives. The remaining items require nouns. That grouping is more useful for repair than a raw twelve-item total because it tells you which grammatical decision failed.

After the first attempt, cover the answer column and try a new sentence using the same family in another role. Change a clear explanation helped us into the tutor explained the method clearly. Producing both forms shows more control than recognising the noun after repeated practice.

## Distinguish a family error from a spelling error

A family error selects the wrong grammatical form, such as explain after a clear. A spelling error selects the intended form but produces explanasion. A length error chooses a plausible word that does not fit the exact gaps. Each cause needs a different repair.

__Original diagnostic examples; invented errors are deliberately incorrect.__
| Error                                    | Cause to investigate        | Repair                                              |
| ---------------------------------------- | --------------------------- | --------------------------------------------------- |
| a clear explain                          | Wrong word class            | Practise verb-to-noun sentence pairs                |
| explanasion                              | Spelling sequence           | Write the correct word, cover it and reproduce it   |
| solution where two solutions is needed   | Missing plural              | Check quantities and agreement                      |
| accurate after reported in this sentence | Adjective instead of adverb | Contrast noun modification and action modification  |
| A word with too many letters             | Ignored gap length          | Compare the visible input pattern before committing |

Do not treat every mistake as weak vocabulary. If you can define the word and use it orally but cannot spell its suffix, retrieval and spelling work are more appropriate than reading another definition. If you spell the noun accurately but place it where a verb belongs, focus on sentence structure.

Check the completed sentence aloud during untimed review. It can expose missing agreement or a form that sounds wrong in context. During a timed attempt, use a short mental reread rather than a spoken review that would conflict with test conditions.

For related sentence-control work, use the [embedded-question drills](/articles/toefl-embedded-question-word-order). Grammar checks are most useful when each targets an observed pattern. Trying to remember an entire grammar book at every gap can make the routine slower and less reliable.

## A fifteen-minute production session

Use our suggested routine: three minutes reviewing yesterday’s two errors, five minutes producing forms in new sentences, five minutes on an unseen short gap set and two minutes recording the cause. Fifteen minutes is a manageable study block, not a research-based requirement for vocabulary growth.

* Choose two families from real recent errors.
* Write one sentence requiring a noun and one requiring another form.
* Cover the model and produce the missing ending from memory.
* Complete a fresh set without checking answers mid-attempt.
* Classify each miss as meaning, grammar, length or spelling.
* Repeat resolved words later in a new context rather than immediately ten times.

Keep the record small. For each family, one correct contextual pair and a later retrieval date are enough to start. A list of hundreds of isolated terms may feel substantial while hiding whether you can produce the relevant form under a timer.

Increase difficulty by reducing support, not by inventing rare vocabulary unrelated to your errors. Move from choosing among forms to supplying a full form, then to completing only the missing letters. Finish with a fresh paragraph so the skill returns to comprehension rather than remaining an isolated spelling game.

The [eight-week working plan](/articles/toefl-eight-week-working-plan) places these short drills between larger checkpoints. If you already produce the forms accurately, shift time to the next recurring problem rather than extending the drill merely because it is easy to measure.

## Check the skill in reading and writing

Reading gap production and Writing word choice overlap, but the input constraints differ. In a gap, the prefix and letter spaces restrict the answer. In an email or discussion, you choose the word freely and need it to express the intended meaning appropriately.

Create a fresh email sentence such as the new arrangement would make the schedule more flexible, then check that flexibility is used where a noun is needed. This tests the family in a productive task. Do not insert a newly learned word if a simpler expression communicates more naturally.

Take topin’s [free TOEFL mock](/toefl/practice-test), marked on the official scale, to see whether accurate forms survive complete timed work. Its estimated bands are separate from the drill score. Twelve correct rehearsed sentences do not predict an official Reading or Writing band.

If word endings improve but passage questions remain weak, inspect evidence and inference rather than continuing to call the problem spelling. If the gap is still wrong, compare the visible letters, exact input length and sentence grammar before choosing a new drill.

The useful outcome is a smaller set of recurring errors and accurate production on new material. A vocabulary list becomes valuable when it changes what you can actually type in context, not when its length becomes impressive.

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## FAQs

Is this an official TOEFL vocabulary list?

No. The families and drills are original study examples. ETS’s task descriptions define the skill; this article does not claim to predict the words you will see.

Do suffixes always identify word class?

They are useful clues, not universal rules. Verify the actual form and use the sentence, visible letters and gap length together.

Are these full Complete the Words paragraphs?

No. They are explicitly single-sentence ending drills to isolate form and spelling. Return to fresh current-format paragraphs for a complete task rehearsal.

Should I type the whole word?

Use the actual task’s instructions and input. These drills show whole words for review but identify missing letters separately so you practise respecting the shown prefix.

Can I prefer British spelling in every gap?

Follow the visible letters and exact spaces. A spelling preference cannot override the pattern supplied by the item. Our article copy uses British English.

## Sources (checked 5 October 2026)

* [ETS: current Reading skills and task types; checked 5 October 2026](https://www.ets.org/toefl/test-takers/ibt/about/content/reading.html)
* [ETS: 2026 task specifications; checked 5 October 2026](https://www.ets.org/content/dam/ets-org/pdfs/toefl/toefl-ibt-test-specifications-2026.pdf)
* [ETS: 2026 Practice Test 1 directions; checked 5 October 2026](https://www.ets.org/content/dam/ets-org/pdfs/toefl/toefl-ibt-full-length-practice-test-1.pdf)
* [British Council: word building and suffix clues; checked 5 October 2026](https://learnenglishteens.britishcouncil.org/exams/grammar-vocabulary-exams/word-building)

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