The structure of a language analysis is similar to that of a text response except you're analysing the way in which things are said to portray an opinion rather than how parts of the text contribute to a whole picture.
Introduction: The title of the article/ speech/ dialogue, the author, the issue and why it is an issue, the authors contention, the tone they use to try to persuade the audience.
Body: Talk about how the author tries to persuade the audience to share their point of view so through tone, appeals, persuasive language techniques, etc. Try not to just state the technique and what it is, try to weave it in while evaluating the article. Think about what is said, how it is said, how the writer is attempting to position the reader and the effect of it, both its intended and actual effect.
Conclusion: Do NOT summarise or restate your essay. You have to evaluate it, as it is an analysis. Comment on the articles effectiveness, whether it is or isn't effectively persuasive and why.
That's basically the foundation of it but different teachers sometimes prefer students to structure and analyse differently so it's best to consult your teacher on the way they would like you to do it beforehand to enhance your chances of doing well. People do their best when they with certainty what they're doing.