# Phase 5: NLP, Foundations to Advanced > Language is the interface to intelligence. Master every layer. ## Start this phase on GitHub **Prerequisites:** Phase 2 Lesson 14, Naive Bayes. Python 3.11+ is enough for the first lesson. **First lesson:** [Text Processing](01-text-processing/) Run this command from the repository root: ```bash python3 phases/05-nlp-foundations-to-advanced/01-text-processing/code/main.py ``` Keep the command, exit code, token list, stems, lemmas, and one example where stemming loses meaning but lemmatization preserves it. **Next action:** Add one sentence with punctuation and an irregular verb, inspect the result, then continue to [Bag of Words and TF-IDF](02-bag-of-words-tfidf/). Browse the [full Phase 5 lesson list](../../README.md#phase-5) or the [cross-phase roadmap](../../ROADMAP.md).