Prefixes Com- and Sub- — Together and Under

Word-flip retrieval: teacher writes pairs (combine/divide, connect/disconnect, submarine/airplane, subway/highway) and asks 'which one has a prefix that means TOGETHER or UNDER?'

• Affirm com-/con- = together
• Affirm sub- = under
• Bridge to formal naming

Two new prefixes today. COM- and CON- both mean TOGETHER or WITH. They're the same prefix; the spelling changes depending on the root sound. COM- before b/m/p (combine, common, compete, communicate). CON- before most other letters (connect, contact, conduct, contain). Look at MG-9. Examples: combine = COM (together) + bine (root). Connect = CON (together) + nect (root, meaning to fasten). SUB- means UNDER or BELOW. Submarine = SUB (under) + marine (water, sea) → 'under the sea.' Submarine literally means under-sea-craft. Subway = SUB + way → under-way. Subtract = SUB + tract (pull) → pull under, take away. Subzero = SUB + zero → below zero. Today we DETECTIVE — find the root inside, recall the prefix meaning, predict the whole-word meaning. Then check.

• Prefix + root predicts the meaning.

  model Prefix: SUB (under). Root: MARINE (water/sea). Predicted meaning: 'under the sea.' Real meaning: a craft that goes under the sea. ✓

  prompt Strip and predict: SUBMARINE.
• Even a hard word becomes guessable with the routine.

  model Prefix: SUB (under). Root: TERRA (Latin for earth). Predicted: under the earth. Real: existing or occurring beneath the earth's surface. ✓

  prompt Detective on SUBTERRANEAN (a stretch word).
• Almost always works.

  model Prefix: COM (together). Root: BINE (related to bind, to tie). Predicted: tie together. Real: join two or more things to make one. ✓

  prompt Detective on COMBINE.

• What does SUB- mean?
• Why does COMBINE start with COM- instead of CON-?

M-3-F-VOC-16-A Chart

Reproduction of MG-9 top section at 11x17: row 1 COM-/CON- (blue, 'together / with') with 5 examples in tile-form (com+bine, con+nect, com+pare, con+duct, com+municate); row 2 SUB- (red, 'under / below') with 5 examples (sub+marine, sub+way, sub+tract, sub+zero, sub+merge). Each example shown as separate magnetic-tile-style components with a + between. Print-ready, dyslexic-friendly font.

MG-9 Chart Physical / non-image

Affix and Latin root anchor poster: top section PREFIXES — COM-/CON- (means 'together / with') with examples combine, connect, compare, conduct; SUB- (means 'under / below') with examples submarine, subway, subtract, subzero. Middle section SUFFIXES — -TION (means 'act, state, or result of') with examples action, motion, attention, direction; -MENT (means 'act, state, or result of') with examples movement, payment, agreement, government. Bottom section ROOTS — ACT (do): action, react, actor. PORT (carry): import, export, portable. STRUCT (build): structure, construct, instruct. JECT (throw): inject, eject, project. FORM (shape): form, inform, transform. Each row color-coded; root family branches diagrammed. Print-ready 11x17.

• Build 6 prefix words using the magnetic tiles (com-/con- or sub- + root). Read each aloud. Predict the meaning.

  scaffold Tiles + MG-9 + magnetic board
• Detective on 6 new words: submarine, subway, subzero, combine, connect, contact. Strip the prefix; predict; check.

  scaffold Detective worksheet (prefix | root | predicted | actual columns)

• Strip SUBTRACT: prefix, root, predicted meaning?
• Build one new SUB- word and use it in a sentence.

• Hold up your detective worksheet.
• Predict: tomorrow we meet -TION and -MENT and Latin roots.

• Find one COM-/CON- or SUB- word in a book at home. Strip the prefix. Write the root and predicted meaning.