My personal opinion is you should do your A/L in Sinhala medium. Judging from the language you have used in your question, your English proficiency may not be sufficient to handle A/L. However, if your Sinhala is as bad as your English, you had better do your O/L again in Sinhala medium.

As l see there are two factors affecting to your decision
1. Your ability and speed when writing in Sinhala. Do not undermine this, It has a huge impact in exam. if you are comfortable in writing your answers in Sinhala and your writing speed is okey, then go ahead

2. The subject area that you follow .If you are doing commerce or technical subjects better to do it in English medium but if you are doing science and maths streams you need to focus on the language which you can understand the most since subject matters get extremely complex in the course content

Hope this helps and wish you all the very best.!!

Your first target should be selection of university. If you can achieve that in English medium please transfer to Sinhala medium. Otherwise you may missed your university target.

Dear Student,
To select the medium you want to face A/L exam. You should think both languages competency level for A/L exam. So you better select most relevant language.

According to my opinion and knowledge, I think If you can assure that you can achieve your university target by doing English medium, you can follow it. The most students who are doing English medium or Sinhala medium are selected to university degree programs due to their dedication, and courage. And also your decision on your medium depends on subjects you wish to select. As an example if you choose ICT for AL, its better to do it in English, due to many words in ICT section is in English. Like that.

If you're not choosing subjects from Arts Stream go ahead with English Medium. As you did O/L in English medium hopefully you will have sufficient English knowledge in understanding a question. But changing your medium might affect your performance and speed.
Thank you

Dear student,
the GPA system and the competition level for both medium are equal, you should check whether there are expertised teachers for English medium and the sufficient books and reference materials available.
my choice is your mother tongue is good to perform, your English medium in O/L will help in university level.
Thank You
Kind regards

Dear
In which stream you are going to do A/L. If you are going to do commerce stream choose English medium.

As you have done your O/L in English medium, it is better to do A/L ICT also in English medium. Competition level for the both medium is equal. For Learning process both medium can be used. English medium is easier than Sinhala.

She / he can do her A/L in English Medium. It is good for her future career also. Anyway after A/L she / he has to do his higher education in English medium.

In Sinhala medium stream has lot of experienced teachers and lot of good tuition teachers also available. But difficult to find experienced and good teachers and tuition classes in English medium stream.

Your Parents are correct in some way. The Current situation is very competitive. I would like to say if you have trust and proficiency in English Language O K, A/L go ahead. Its very timeliness, and all over the world job fields are available other than the Art stream. If you wish to do Art stream do it in a Sinhala medium.

Your English seems to be below the required level and therefore your parents' advice to do A/L in Sinhala medium is to be considered.

Dear Student,
Better to follow A/L in English medium. It is easy to do. English terms are easy and you can follow many extra references from books and internet too. also once you enter any University, the medium is English. My advice is to continue your studies in English medium.

Hi Umashi Kavya,
First and foremost, I would like to appreciate your enthusiasm in making the right decision to continue with your A/L studies.

To answer you question, I would recommend you to follow your A/L in English Medium for the following reasons:
1. You will be more prepared to continue your higher education, which will be in English Medium.
2. You can find learn resources in English easily.

Considering your parents point, according to my knowledge the GPA for both the mediums is same. Hence the medium you choose is not going to affect your entrance to the university.

However, if there is a will, there is a way; if you really set a goal to enter the university, believe in yourself, dream about it, and dedicate yourself to achieve it; nothing else matters!

I wish you the best of luck in all your future endeavors!

Firstly; the selection process is based on the ZED score, irrespective of the medium of Language.
So the selections are NOT effected as per the Language you sit the exam in.

Secondly, Most Degrees, whether Local or Foreign are conducted in English. The English terms are easier to learn and master than in Sinhalese when it comes to any form of studies. By making a glossary / list of words per lesson, with their meanings and studying them separately will make it easier to answer and score at questions.

According to my opinion and knowledge, English medium is the best option. but it is depending on your English knowledge.

Dear Putha,
If you completed your O/L in English medium you have the capacity to do the AL in English medium, there are more opportunities in the campus if you more fluent in English language. But the selection criteria is same to the all the medium. AL is not like simple as OL so there is more competitive to enter the university.
Thank You,

I have done my O/L's in Sinhala medium and I have chosen the Commerce stream. In which medium should I do it?

මම O/L ශිෂ්‍යාවක් වෙමි. මම කරන්නේ සිංහල මාධ්‍ය නමුත් මම කැමතියි A/L ඉංග්‍රීසි මාධ්‍යයෙන් කරන්න. මම A/L කරන්න ඉන්නේ ගණිත අංශයෙන්. මට ඒක කරන්න පුළුවන්ද?

I was do subjects in Sinhala medium during O/L. Now I will do A/L in commerce subject. But when I choose the subject of commerce, I think, I want to do it in English medium because is that better for future. My English ability is normal.
Is it okay to do that? Or do not do it? Because there are difficult words in commerce subject, will I not be able to clear that subject?

Hello, I am an A/L bioscience student. I did my O/L's in Tamil medium. Now my question is which medium is better to study A/L Bioscience?
(Note:- I have a little fluency in English Language)