1. learning subjects: English, math, science, etc.

2. subjects to learn:English, math, science, etc.
3. studying subject:English, math, science, etc.
4. subjects learning:English, math, science, etc.
5. taking subjects:English, math, science, etc.
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Which title on the left is suitable and correct?

I'm not sure what this is for, mainly because you're not using full sentences.

Full sentences --

I'm learning these subjects: English, math, science, and a few others.
I'm studying these subjects: English, math, science, and a few others.
I'm taking these subjects: English, math, science, and a few others.

1. Learning Subjects: English, math, science, etc.

2. Subjects to learn:English, math, science, etc.
3. Studying Subject:English, math, science, etc.
4. Subjects Learning:English, math, science, etc.
5. Taking Subjects:English, math, science, etc.
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Thank you.
Can we use the title on the left?

What title on the left? Are you trying to write a title for a paper or a story? or what?

ALWAYS put a space after a colon.

All of the titles on the left are suitable and correct, as they effectively convey the idea of learning or studying various subjects such as English, math, and science. The specific phrasing may vary slightly, but they all accurately communicate the same concept.