Sentence improvement — Word order and the split infinitive in a directive: assess ‘‘I want you to clearly understand that excuses won't do’’ and decide if any rearrangement is required for modern standard English.

Given data
I want you to clearly understand that excuses won't do.

Concept/Approach
Split infinitives (‘‘to clearly understand’’) are widely accepted in contemporary English, especially when they improve clarity and rhythm. The pronoun placement ‘‘I want you to …’’ is also standard.

Option analysis
you clearly to understand — Unnatural word order.you to understand clearly — Acceptable, but no need to move the adverb; current placement is fine.to clearly understand you — Changes the object (misleading meaning).No improvement — Best choice; modern, clear, idiomatic.

Verification/Alternative
Alternative: ‘‘I want you to understand clearly ...’’ (also correct). The given version is not erroneous.

Common pitfalls
Treating all split infinitives as wrong—this is a myth; clarity takes precedence.

Final Answer
No improvement