The error you’re experiencing usually occurs when the required spaCy English language model isn't installed. `en_core_web_sm` is a small English model trained on web text from spaCy, another popular Natural Language Processing (NLP) framework that NLTK often works together with. The error suggests that Python's spaCy module is looking for this language model and not finding it in your environment. To resolve this issue, you can install the missing model by using the following pip command: ```python !python -m spacy download en_core_web_sm ``` Run this in your preferred IDE or in your terminal/command prompt. Once the language model is downloaded and installed, you should be able to load it through spaCy as follows: ```python import spacy nlp = spacy.load('en_core_web_sm') ``` Remember to restart your Python environment after the download if you're running this in a Jupyter notebook. When programming in the domain of NLP using NLTK or spaCy, it's essential to ensure you have installed all the necessary language models. These models have trained data that the libraries use to perform various tasks such as tokenization, lemmatization, part of speech tagging, etc. Each of these tasks contributes towards understanding and processing the semantics of the text.