Final answer:
The sentence 'no entendo la lección' is grammatically incorrect as written in Spanish. The correct sentence should be 'no entiendo la lección'.
Step-by-step explanation:
The sentence 'no entendo la lección' is grammatically incorrect as written in Spanish. The correct sentence should be 'no entiendo la lección'.
The incorrect form 'no entendo' should be corrected to 'no entiendo' to match the correct conjugation of the verb 'entender', which means 'to understand'. Additionally, the correct spelling of 'entender' should be used in the sentence.