Suffixes -cious and -tious Word Search

DELICIOUS or DELITIOUS? CAUTIOUS or CAUCIOUS? The -cious and -tious suffixes are the last of the tricky adjective endings, and they follow a rule similar to -cial/-tial but with a different anchor: the related noun decides the spelling.

This word search contains ten -cious words and five -tious words, designed for Year 5 and Year 6 pupils, and for fourth and fifth grade readers in the US. This is the penultimate puzzle in the entire Series A collection — a milestone worth marking. Larger grid, words left-to-right and top-to-bottom only.

PRECIOUS · DELICIOUS · GRACIOUS · SPACIOUS · VICIOUS · CONSCIOUS · SUSPICIOUS · FEROCIOUS · AMBITIOUS · CAUTIOUS · INFECTIOUS · NUTRITIOUS · LUSCIOUS · MALICIOUS · VIVACIOUS

The last of the tricky adjective endings

-cious appears in words where the related noun ends in -ce or -cion: GRACE → GRACIOUS, SPACE → SPACIOUS, MALICE → MALICIOUS, SUSPICION → SUSPICIOUS, VICE → VICIOUS, FEROCITY → FEROCIOUS. -tious appears where the related noun ends in -tion: CAUTION → CAUTIOUS, NUTRITION → NUTRITIOUS, INFECTION → INFECTIOUS, AMBITION → AMBITIOUS. The noun’s last few letters predict the adjective’s ending: -ce/-cion gives -cious, -tion gives -tious.

This is the third puzzle in a row built on noun-adjective pairings (S63’s -ance/-ence pair with S64’s -ant/-ent, and now S67’s -cious/-tious pair with their noun families). The principle is the same: learn the family relationships, and the spelling sorts itself. A child who knows CAUTION sees CAUTIOUS as its adjective form, and the -tious ending is the giveaway. The hard part is knowing the noun — once that’s secure, the adjective spells itself.

Five words to connect to their nouns

1. CAUTIOUS comes from CAUTION. Write CAUTION above CAUTIOUS and ask your child to spot the shared letters: C-A-U-T-I-O. The adjective just adds U-S. The noun’s -tion has become -tious, like S47’s -tion family wearing a new costume.
2. DELICIOUS doesn’t come from DELITION (not a word). Tell your child plainly: DELICIOUS is a -cious word but with no -ce or -cion noun partner. Some words just have to be learned. Honesty about exceptions makes the rule more trustworthy, not less.
3. AMBITIOUS comes from AMBITION. AMBITION is what you want to achieve in your life. Ask your child what their ambition is right now — be a footballer, a vet, a YouTuber. Then point at the spelling pair: -tion to -tious.
4. SPACIOUS comes from SPACE. A spacious room has lots of space. Ask your child to describe the most spacious place they have been (a museum, an airport, a field). The noun-to-adjective bridge here is the cleanest one in the puzzle: SPACE + -ious = SPACIOUS (the E drops — S33’s rule still on duty).
5. CONSCIOUS is the trickiest in the grid. The noun is CONSCIENCE, but the adjective is CONSCIOUS — and the noun for being aware is CONSCIOUSNESS, not CONSCIENCE. Two different but related noun-adjective trios live here, and one of them shows up in S39’s -ness family. Word families overlap.

Three ways to match nouns and adjectives

As a noun-finding starter. Write each grid adjective on the board and ask the class to supply the noun: DELICIOUS → ? (no clear noun in common use). CAUTIOUS → CAUTION. SPACIOUS → SPACE. NUTRITIOUS → NUTRITION. The exercise reveals which words follow the rule cleanly and which don’t. The clean ones cement the rule; the awkward ones teach honest exceptions.

As a noun-to-adjective conversion pair task. One child says a noun (CAUTION, AMBITION, SPACE), their partner converts to the adjective and finds it in the grid. Swap each turn. The conversion move — noun ending tells adjective ending — is rehearsed a dozen times in five minutes.

One-to-one at home. For home educators, ask your child to write a one-paragraph review of a meal — breakfast, dinner, anything — using at least four grid adjectives. “Breakfast was DELICIOUS and NUTRITIOUS. The toast was PRECIOUS (a bit dramatic, but allowed). The orange juice was LUSCIOUS.” Real adjectives describing real food makes the suffix work double duty: spelling practice plus descriptive writing practice. The paragraph might go on the fridge.

What comes next

• Difficult homophones word search — the final puzzle in Series A: the words even adults confuse
• Suffixes -cial and -tial word search — the previous puzzle in this series
• All spelling word searches — the full series from foundation phonics to Year 6

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