How do I write an effective cover letter?

Hello, world! I’m a chemical engineering graduate (graduated in 2015) trying to change my field/career to software engineering. I’ve been learning computer science and programming since the start of 2016 via books, MOOCs, and other online courses. I’ve now started to apply for internships. What can I write in my cover letter to convince employers to consider me for an internship? Please note that a lot of software engineering internships require you to be a computer science student, so you must provide strong reasons for them to hire you. Also, I don’t have any official projects under my belt. A lot of the assignments in MOOCs are mini-projects themselves, and I can’t share them on my GitHub as doing so violates the Honor Code.
Any sort of help or advice is appreciated. Thanks in advance.

Here’s how I usually format mine:
[Company Name]

[Position You Are Applying For]
First paragraph: Introduce yourself! Who are you? Where are you located? Are you willing to relocate? What are you currently doing / have done most recently? How did you hear about the job? (For this one, I usually mention a specific project the company has done, tell them that I really liked x and y about it, and would love to join the team on future projects.)
Second Paragraph: This is where you write a little bit more about your relevant experience. Don’t worry, if this is the beginning of your career change, explain what you did before and why you’e looking for a career change, specifically why you’re changing from x into computer science and programming. Also, list any previous skills or recent skills that you have that is relevant. It’s also up to you whether you want to mention that you were self taught. I would mention, in detail any projects you worked on before that, though.
Third Paragraph: This is where you write what YOU can do for the company. Have a good look at the job description. Study it. What are your daily responsibilities that the company is expecting of you? With this in mind, look up similar job postings. Study their job description. Pull out a thesaurus. I’m serious. For example, if the job says you have to make and maintain relationships with businesses who are looking to market with [company](totally irrelevant to tech, I know, but for the sake of example…) then you write " I will create and elevate strategic partnerships with brands that are looking to work alongside major influencers within the beauty community to drive traffic to their social commerce platform. Be as specific as possible. You might even have to research their current clients. It sounds like a lot of work, but the company will see your enthusiasm to work with them, so if you have any ideas, projects in mind, or anything that you can bring to the company, write it here.
[closing, such as “Warm Regards”]

[Your Name]

[Contact Number]

[Email]
I hoped that helped, and good luck :slight_smile:

I used to do this for a living a few years ago. Nothing much has changed since then. Here ya go!
A cover letter should be looked at as a complement to your resume or CV. It should not be a duplicate of it, nor part thereof.
You can really make a cover letter work for you if you are smart enough. Here’s why: When employers ask for a cover letter, they are not doing it for the benefit of their health. They are doing it for a reason, and that is mainly to see how you conduct yourself on paper, so to speak. This exercise can evaluate your spelling and grammar talents, show your ability to put words into sentences to make meaningful paragraphs. They can also gauge your comprehension talents as well. So DO NOT let anyone tell you that it is not important. It is far more important than your resume.