I’m Diane Costa, a GCSE and A-level examiner with over ten years as Head of Chemistry and an MSc from King’s College London. I teach ambitious students one-to-one – at home in London or online.
The tutor
“[Diane] has excellent subject knowledge and she is able to explain complex concepts clearly for students to understand.”
In more than ten years as Head of Chemistry, I led curriculum development and departmental strategy, and mentored junior teaching staff.
I have taught for 16 years and hold Qualified Teacher Status. Today I am Chemistry Subject Specialist and Head of Year 11 at a London secondary school, and a GCSE and A-level examiner. Since 2016 I have also tutored privately. As an experienced educator and a parent, I know how much these years matter to the whole family.
Tuition
One-to-one lessons at your home in London or online, each shaped around the student’s goals – from securing the foundations to reaching for grade 9 and A*.
My specialism
AS and A-level Chemistry for every exam board: deep understanding first, then the precise technique that turns it into marks.
The Examiner Advantage
I teach in the classroom and mark GCSE and A-level papers. My lessons cover the chemistry in depth, and exactly how examiners read and reward an answer.
“…great tips focussed towards exam questions as an examiner herself.”
Students see exactly what earns credit, and why.
I identify common errors before they cost grades.
Students learn strategic exam technique alongside content mastery.
I mark practice papers with an examiner’s eye.
I keep this knowledge current through examiner standardisation meetings and subject conferences.
Oxford, Cambridge & Medicine
A-level Chemistry taught to the top grade by an examiner, with stretch beyond the specification for students aiming at Oxford, Cambridge and Medicine.
No tutor can promise an offer, and I do not. What I offer is rigorous teaching that builds depth, precision and confidence.
Secure understanding first, then the precise answers that mark schemes reward, for every exam board.
Unfamiliar problems beyond the specification, for students already working at the top grades.
Ideas from the course followed further, with recommended reading to extend understanding.
The method
I break challenging topics into clear, logical steps. The aim is genuine understanding and independent thinking, never rote memorisation.
A secure grasp of the fundamental principles, so that harder ideas have something solid to rest on.
Theory connected to its practical applications, so the science makes sense beyond the exam room.
What examiners look for, and exactly how to deliver it.
Patient, targeted support for students who find core concepts difficult; stretch and challenge for high achievers.
Reviews
Families have been very happy with the progress and results – 63 of my 64 reviews on First Tutors are five-star.
“Daiane is an experienced chemistry teacher and examiner so was an obvious choice to help my daughter improve her exam grades.”
“Daiane is a very pleasant and excellent Science teacher. We were very impressed by how quickly my daughter boosted her confidence with Science exam questions thanks to Daiane’s lessons.”
“She came to our home for the sessions, which was a great convenience, and she quickly created a calm and productive learning environment. Our son really appreciated her teaching style—he felt supported rather than pressured, which helped him engage more easily with the subject.”
“Daiane is very professional and experienced with her teaching. My son is in Y11 and had many tutors in the past, he always achieves 8 or 9 on his science exam. He commends Daiane is one of the best, very knowledgeable tutor with great responsibility and kindness. Definitely recommended.”
“Daiane tutored me from February up until my A Level Assessments in May. Daiane was very helpful in building my confidence at the end of my course… She was very supportive and understanding. It was very useful having a chemistry teacher who is currently teaching A Level…”
A selection, quoted verbatim from First Tutors, where my name appears as Daiane.
Fees
Clear fees for 60-minute lessons that I plan and teach myself. There are no registration or other fees.
Included: a personalised study plan, all materials and practice questions, regular feedback, support between sessions by email – and travel, for lessons at your home.
CancellationsNo charge with six or more hours’ notice. With less than six hours’ notice, the full session fee applies.
At your home in London
£85
per hour, one-to-one
Online
£75
per hour, one-to-one
Questions
Anything else? Ask it in your enquiry, and I’ll reply.
A-level Chemistry is my specialism – AS and A-level, for all exam boards. I also teach GCSE and IGCSE Chemistry, Biology and Physics (Triple Science, and Combined Science at Foundation and Higher tier), KS3 Science for ages 11 to 14 and university-level chemistry. My students include adult learners, students re-sitting exams, students with SEND, and home-educated and international students.
Both. One-to-one lessons take place at your home in London (travel included, up to 6 miles) or online, on Google Meet or Zoom, for students anywhere in the UK and internationally. Small groups of up to six KS3 or GCSE students meet online.
Lessons are 60 minutes. I teach on Monday, Tuesday, Thursday and Friday evenings from 6 pm, and Saturdays from 8 am; the last lesson of the day starts at 8 pm.
All the major boards. For GCSE and A-level: AQA, Pearson Edexcel, OCR (A and B) and Eduqas. For IGCSE: Cambridge and Pearson Edexcel International. As a practising GCSE and A-level examiner, I know how mark schemes and assessment criteria are applied, and the common pitfalls that cost students marks.
Yes, with the chemistry: A-level Chemistry taught to the top grade, and stretch and challenge beyond the specification for high achievers, at my standard fees. I do not provide coaching for admissions tests, interviews or personal statements. Read more about Chemistry for Oxford, Cambridge and Medicine.
Yes. I hold a current enhanced DBS check. My qualifications, identity and two professional references have also been verified by First Tutors.
Every student has a personalised study plan with clear, achievable targets. I track progress regularly and give feedback at the end of each lesson – something many parents mention in their reviews – or send written feedback afterwards, with homework. Students can also email me between sessions.
Begin
A grade 9, an A*, a place to read Medicine, or simply renewed confidence. Share the goal and I’ll reply to discuss how I can help.
Use the form, or send me a message on WhatsApp.
I’ll be in touch to discuss what the student needs, and whether lessons at home or online will suit best.
We agree on your child’s needs before the first lesson, then set clear, achievable targets aligned with the grade they are aiming for.
I track progress throughout, with feedback at the end of each lesson.
Prefer to message?
Message on WhatsApp (opens in a new tab)All fields are required unless marked optional.