O/L Subjects List Sri Lanka — Subject Selection Checker

A Sri Lankan G.C.E. (Ordinary Level) candidate offers exactly 9 subjects: 6 that every candidate takes, and 3 chosen from three separate categories of optional subjects. There is no arithmetic in this tool — the answer is a set of membership and exclusion tests run against the subject structure published by the Department of Examinations and the Ministry of Education. All five tests are shown on screen, with the source of each named beside it, so the method is visible rather than hidden in the code.

1. The count rule. 6 compulsory + 3 optional = 9 subjects. Nothing more, nothing fewer.
2. The compulsory set.Religion, First Language (Sinhala or Tamil Language & Literature), English Language, Mathematics, History and Science. Exactly one religion subject from the five offered, and exactly one first language. An English-medium candidate still offers Sinhala or Tamil as their first language.
3. The category rule. This is the one that catches people. Writing the chosen optional set as O and the three categories as G₁, G₂, G₃, a legal selection satisfies |O| = 3 and |O ∩ Gᵢ| = 1 for every i. Two subjects from one category necessarily leaves another empty, so the tool reports both halves of the failure and offers the swap that fixes it.
4. The second-language exclusion. Category I carries the two national second languages. The one open to you is the one that is not your first language: Second Language (Tamil) for a Sinhala first language, Second Language (Sinhala) for a Tamil first language. This is the only rule on the page that depends on who you are rather than on what you picked — the same subject is legal for one candidate and not for another.
5. The duplicate exclusion. No subject appears twice across the 9.

Two results are kept apart on purpose. A form that is not finished is reported as incomplete, with the remaining categories named — not as a broken rule, because a student halfway through a form has not done anything wrong. A finished selection that fails is reported as not allowed, with the specific rule quoted.

Every verdict is also re-counted by a second, independent route: the finished nine-row table is walked row by row, the way a clerk checking an application by eye would, and the totals are compared with the rule engine's own bookkeeping. The tool prints that agreement under the result, along with the number of hand-worked cases it reproduces. Those cases were derived by hand from the rules above before the code was written, and they run in your browser each time the page loads — if the data ever drifts from the worked examples, the count on screen drops.

One thing the tool cannot tell you: whether your school actually teaches the subject you picked. Category membership is a national rule; the timetable is a school decision. A legal selection your school does not run is still a dead end, so confirm with your class teacher before the application goes in.

All 38 optional subjects, in the three official categories. You take exactly one subject from each table. Subject names are as the National Institute of Education syllabus names them, with the Sinhala-medium name beside each where the subject is taught in Sinhala.

The 6 compulsory subjects are not in these tables because they are not chosen: Religion (one of Buddhism, Saivaneri (Hinduism), Catholicism, Christianity, Islam), First Language, English Language, Mathematics, History and Science.

Your optional subjects do not by themselves choose your A/L stream. Entry to G.C.E. (A/L) is governed by your O/L results — at least six passes in one sitting, including your first language, Mathematics and English. Which subjects you sat matters for what you have studied, not for what you are permitted to do next.

• For the result rule and your credit count, use the O/L pass & A/L eligibility calculator.
• For the three-subject A/L combination rules, use the A/L subject combination validator.
• For which A/L stream a combination opens, use the A/L stream eligibility checker.

Also out of scope: which subject is “easier” or “better” — that is an opinion, not data — and which subjects any particular school teaches, because no national dataset of that exists and a guess would be worse than telling you to ask.

• Department of Examinations, Sri Lanka — G.C.E. (O/L) subject list and examination application
• Ministry of Education, Sri Lanka — G.C.E. (O/L) subject structure
• National Institute of Education — Grades 10–11 syllabus listing (subject names)
• GCE Ordinary Level in Sri Lanka — one of three concordant transcriptions used to cross-check category membership
• Education reform timetable — new Grade 10 curriculum in 2028, first reformed O/L in 2029

The category lists on this page were last checked against these sources on 2026-09-23. Two things are deliberately absent. The two-digit subject numbers printed on the examination application are not reproduced, because the current numbering could not be read off an official Department of Examinations source — copy them from the application itself. And the Tamil-medium subject names are not yet shown, because they have not been transcribed from the Tamil syllabus listing; guessing them would be worse than leaving them out.