Summary of "Transformation of Sentences | ICSE & ISC Grammar | Rules | Boards 2026"

Summary — main ideas

The lesson (ICSE & ISC grammar) covers two sentence-transformation structures commonly tested in board exams:

Transformations between “too … to …” and “so … that …” (including correct use of cannot / could not).
Transformations of sentences beginning with “Only …” into the “None but …” structure.

The instructor explains rules, gives multiple examples, highlights common mistakes, and stresses correct punctuation (use a full stop) to avoid losing marks.

A. “too … to …” ↔ “so … that …” (including cannot / could not)

When a sentence has “too + adjective + to + verb”, it can be transformed into “so + adjective + that + (subject) + cannot/could not + (verb)”, to express impossibility or inability.

Tense rule for inability

Present-tense originals (contain is/are) → use “cannot”.
Past-tense originals (contain was/were) → use “could not”.

Step-by-step transformation (too → so that)

Identify the adjective and verb phrase in the “too … to …” sentence.
Change “too + adjective” to “so + adjective”.
Add “that”.
Use subject + cannot/could not + appropriate verb form (use passive when the original is passive/impersonal).
Preserve tense: present → cannot; past → could not.

Examples

The bag is too heavy to carry. → The bag is so heavy that it cannot be carried.
The story was too boring to finish. → The story was so boring that it could not be finished.
The ladder is too short to reach the window. → The ladder is so short that it cannot reach the window.
The movie was too long for us to stay till the end. → The movie was so long that we could not stay till the end.
He is too weak to lift the box. → He is so weak that he cannot lift the box.

Special note on sentences expressing a resulting action

If a “so … that” sentence indicates someone definitely does something (not inability), the “too … to” form must preserve that meaning by using a negative after “to”. Example:

He is so ambitious that he overworks himself. → He is too ambitious to not overwork himself.

Be careful: dropping the “not” or misplacing negation will change the meaning.

Additional points

The transformation works both ways (you can go from “so … that … cannot/could not” back to “too … to …”).
Use correct punctuation — a full stop is important (teacher warns missing punctuation may cost marks).

B. “Only …” → “None but …”

Purpose: Emphasize that only a particular person/group can do something — no one else can.

Transformation rule

Replace “Only + (person/group) + …” with “None but + (person/group) + …”.
Do not add extra words — “none but” already carries the meaning of “only”.

Prohibited / incorrect forms

Do not use “no other” in this transformation.
Avoid “none other than” and “none but only” for these cases — these are incorrect here.

Examples

Only a brave soldier can handle this mission. → None but a brave soldier can handle this mission.
Only a wise man can give such advice. → None but a wise man can give such advice.
Only a skilled surgeon can perform this operation. → None but a skilled surgeon can perform this operation.
Only a true friend will stand by you in hard times. → None but a true friend will stand by you in hard times.

Common mistakes to avoid

Using the wrong auxiliary for tense (use cannot for present, could not for past).
Omitting or misplacing the negative (“not”) in tricky conversions (e.g., the ambitious/overwork example).
Using incorrect substitutes for “only”: avoid “no other”, “none other than”, “none but only”.
Forgetting punctuation (a missing full stop may cost marks in exams).

Closing

The instructor encourages liking, sharing and subscribing to the channel for more English/economics/commerce content and wishes students well in their exam preparation.