Capitalising school subjects

[Sped Tiger]

I am really confused by this topic, friends, and have been trying to sort it out for a long time already; however, nothing seems to work. I hope you do manage to help me find the right answer, buried very deep on the Internet.
My English teacher said that all school subjects had to be capitalised, and I began trying to figure it out. Almost all I've found says that only when talking about some specific ones, we have to capitalise them.
So, a few questions have arisen (I hope you answer them), viz.:
1. Maybe it's actually optional and old fashioned capitalising all subjects all the time (except for languages and some specific ones), e.g.: I'm like (biology, English, and chemistry/Biology, English, and Chemistry)?
2. If so, can we also capitalise them when they're used adjectively, e.g.: My (chemistry/Chemistry) teacher is very friendly?
3. When it comes to sciences, is capitalising them optional as well, e.g.: I love (linguistics, mathematics, physics, and astronomy/Linguistics, Mathematics, Physics, and Astronomy)?

 

[emsr2d2]

There's no point using "English" as an example in your question. It's capitalised every time you write it!

 

[5jj]

Do not use an initial capital for school subjects except languages.

 

[jutfrank]

This issue is really quite simple—use capitals for names. The problem is—and it is a very hard problem—how to know whether something is a name or not.

If you're referring to a course rather than a subject, you're very likely to be naming the course, in which case you should capitalise:

I'm thinking of changing my major from Computer Science to Applied Linguistics.
She teaches Icelandic Literature in the mornings and Postmodern Studies in the afternoons.
She's enrolled on Nursing and Healthcare.