English Rules: Prohibition and Permission

Prohibition denotes a statement restricting certain actions.
"Can" indicates permission for actions, while "cannot" signifies a lack of permission or rule violation.
Permission represents formal consent to perform an action, often implying that the action is possible.
"Mustn't" indicates that the speaker is establishing a rule against certain actions.

Action verbs express actions taking place, while linking verbs connect the subject to a noun or adjective for clarification.

Modals are auxiliary or helping verbs paired with main verbs to convey various meanings.
"Must" expresses strong obligation or necessity, often from the speaker's authority.
"Have to" indicates an obligation imposed by external authority or general rules.
"Can" communicates allowed actions, while "could" signifies formal or polite allowances in the past.
"May" serves as a formal request for permission; "might" suggests a possibility.

Conditionals express results based on specific conditions, structured as if clause + main/result clause.
Four types of conditionals are recognized:
- Zero Conditional: Used for universal truths, with both clauses in present tense.
- First Conditional: Pertains to likely future events; if clause in simple present, main clause in simple future.
- Second Conditional: Covers unreal present or future scenarios; if clause in past simple, main clause with "would" or "could."
- Third Conditional: Explores hypothetical past situations that did not occur; if clause in past perfect, main clause with "would have."

First Conditional is straightforward, allowing clear communication in formal contexts, often requiring complete sentences and specific language.
Second and Third Conditionals emphasize unreal situations and regrets, respectively, with a focus on more complex structures.
Effective communication entails using appropriate terms, avoiding slang, and maintaining professionalism.