It doesn't matter what programming language you use. Go ahead and use Pascal if it's the best choice for the job.
To be a great programmer, you need to write code that reads like English. We have a framework inside of brains called English speech, reading, and writing. If you're a French speaker, or speak another European language, your framework isn't much different. A great French programmer or a great German programmer will program similarly to a great English programmer. Everybody's seen expressive code. You can look at the code and understand what it does almost instantly. Comments, variable names, abstraction, everything that makes a great programmer, all of these things come into play. Conversely, everybody's seen shitty code that takes several days to understand. I don't care what language it is. You're a horrible programmer if you write code like this. Nobody cares how clever you are, or how you've mastered the specific grammar of a certain language. You will eventually move on and someone else will have to modify your code. The best place for clever code is in the trash bin.
To be a great programmer, you need to be able to plan out what you're going to do in advance. Everybody's worked with hacked together shit, and has had to maintain it. Hacked together shit wastes programmers' time. Spend a few days doing absolutely no "programming" whatsoever. Instead draw some flowcharts, try out a rough prototype, brush up on some theory, write up an estimate, and have someone else review everything.
Learn to be realistic about how long your work will take. I know, genius programmer, you can get everything done in about a day. Be true to yourself and don't try to impress anybody with your speed coding abilities. Take your time, and get it done right. Spend an entire day or several days testing. There's nothing better than a launch that is bug free.
Be prepared to explain your code on a whiteboard to your own mother. If you can't explain what you're doing to your own mother, you don't understand the problem well enough, and chances are you're overlooking something. Your boss will have somewhat more expertise than your mother, but if you can justify what you're doing to her then you're probably on the right track.
Don't be that guy who jumps on every programming fad. If something been around for 20 years, it's probably worth considering. If something's been around for 3 years, perhaps the fad will die out and your company will get stuck maintaining an obsolete framework. Been there, done that.
I don't care if you went to MIT or only high school, we're all equal. You can't go away and work in your little PhD way, emerging a month later with a piece of code that everyone despises. Programming is a team effort. If you think that nobody else can write a piece of code except a PhD, then guess what? Your software is likely to fail, because nobody will be able to maintain it, especially when that PhD leaves to go be a professor at Stanford.
I've seen these mistakes repeated over and over for all 25+ years I've been a programmer.