The learner assignment that asserts more than it can show

Three, and they are different kinds of problem.

1. An unsupported causal claim. Fourteen errors do not establish interference. You have asserted a cause where you have data about a product. And 'Spanish grammar is different from English' is true of every language pair on earth, so it explains nothing.
2. Errors confused with needs. The assignment asks for an analysis of the learner's needs and a rationale for what you would teach. A list of errors is data, not a needs analysis. Missing entirely: why these errors matter to Rosa (care-home work means reporting residents' routines, describing changes, reading care notes); what she says she wants; her learning history and preferences - she watches TV and does not read, which is directly relevant to what you would recommend.
3. Uncited copying. That is an academic-integrity issue that can void the section whatever else is good in it.

The fix is to separate evidence from inference in the writing. 'Of the 14 errors, 3 are plausibly L1 transfer ("I have 20 years" - Spanish uses tener for age; "I am agree" - estar de acuerdo), 6 look developmental (overgeneralised past, e.g. "she goed"), 5 are spelling or lexical.' Counts make the claim honest and the analysis visible.

Small samples are fine if you are honest about them; what is not fine is over-reading them.

• Classify all 14 and report the counts in a small table. Showing the working is a strength: the marker can see the judgement, not just the conclusion.
• Use the data you already have beyond errors. The 10-minute recording tells you about fluency: hesitation, fillers, how she repairs a breakdown. The 12 writing samples tell you about range and spelling. An error list alone cannot tell you her level, and the assignment asks for a profile, not a list.
• Test the interference hypothesis instead of asserting it. For each suspected transfer error, ask whether Spanish actually predicts it. Checking a grammar reference, or asking Rosa 'would you say this in Spanish?', is legitimate evidence - and the second one costs two minutes.
• Prioritise three needs with reasons, and match one activity to each. Fourteen errors with fourteen activities is a list; three with rationale is an analysis.
• Name your framework properly - error versus mistake, interlanguage, developmental sequence - with a citation, so the classification is principled rather than impressionistic.
• Tie it to her context. 'Reading care notes' is a need that follows from her job, not from her errors, and it is the kind of thing the criteria reward.

Twenty minutes' work now, not four days of guilt.

• A direct quotation needs quotation marks, author, year and page. You cannot paraphrase by swapping synonyms and drop the page. Either find the source again (library copy, Google Books preview, the original PDF) and cite it properly, or delete the sentence.
• The third option is usually the best one here: write the point in your own words from your own data. 'A learner's developing system is rule-governed rather than a defective version of the target language' can be written without quotation marks, and if it is a settled idea in the field, one properly cited source is enough - you do not need the famous sentence.
• Never cite what you have not read. If you only know a claim second-hand, either read the four pages or use something you did read.
• Check the policy. Uncited copying usually means the section is not credited and can trigger a formal academic-integrity process, which is a much bigger cost than a weaker sentence.

Then re-check the word count, because citation and re-wording change it.