Why So Many Foreigners Mess Up English?

In spite of learning English for almost half of my life, watching all movies in English and listening to English music, I had a hard time speaking with native speakers. Then I started focusing on my pronunciation and things suddenly improved.

Who doesn't like English breakfast? (Manchester, UK)

Theory

So why is English pronunciation so difficult?

• English native speakers use 16 vowel sounds for 5 vowel letters a, e, i, o and u. On the contrary, in Spanish pronunciation 5 vowel letters correspond to 5 vowel sounds. Many Spanish speakers find English difficult, because they can't pronounce all the English sounds.
• In Slovak, which is my native language, word stress is always on the first syllable. In English, there are more exceptions than rules about word stress. It can be on any syllable. Most Slovaks would pronounce european as YOO r-uh-pee-uh n, while the correct pronunciation is you r-uh-PEE-uh n. Is banana BUH-nan-uh or buh-NAN-uh? Words can also change meaning depending on word stress.
• In German, there are exact rules on how every combination of letters should be pronounced. Learning English and stumbling upon a new word? Look it up in a dictionary. Thought, taught, through and tough — do you think there are any rules?
• English words in a sentence change their pronunciation — and becomes uh nd, uh n or n. What's more, 3 written words can easily become just 1 spoken word. What do you think? (Wə 'ǰyu θɪŋ'k?)
• Does it look complicated enough? There's also sentence stress and intonation, but I'm not covering those. I'm not sure I get them right.

Practice

Enough complaining, let's talk about what you can do as a non-native speaker. Here are a few quick and dirty tips for your spoken English :)

• Practice speaking as much as possible. Attend events with foreigners and expats like language exchanges, Couchsurfing and Internations. If you have that opportunity, spend some time in English-speaking countries or work for a company where English is spoken. It's much better to speak with native speakers, because their accent is perfect and you can learn very much from them.
• Watch English movies or series without subtitles to listen to the conversations rather than read them. Occasionally, pause the movie and try to repeat what the actors say with the same sounds, stress and intonation. Sing out loud your favorite English songs in the shower and try to mimic the original accent (I don't do this for the sake of mental health of my neighbors).
• Reading English text, whenever you look up a new word in a dictionary, don't neglect checking its pronunciation. Occasionally, look up pronunciation of the words you already know, you might have been mispronouncing them for years. Pay attention to word stress, it's really important.

Are you already doing all these things and your accent still sucks?

• Learn to pronounce all the 16 vowel and 21 consonant sounds. This is where most accent reduction courses start. The course I took was The Mimick Method by Idahosa Ness. You first take a pre-test to figure out which sounds make you trouble. Then you spend time with drills for individual sounds and confusing sound pairs (sheet vs. shit). Finally you combine these sounds into syllables and syllables into speech. You do this by memorizing and repeating song lyrics. It was challenging and time-consuming, but worth it. Idahosa thinks the whole world is learning languages backwards starting with reading/writing and moving on to listening/speaking. He suggests starting with pronunciation and is definitely onto something there. I don't regret taking his course and for the next language I learn he's my choice.
• Revise pronunciation of most common English words (500 most common words account for 80% of all conversations). You might have been pronouncing some of them incorrectly for years and it's not that difficult to fix. Maybe nobody told you about word stress back then when you were learning these words, so learn where the stress is in each word now.
• Learn to connect words, use sentence stress and intonation. You can either do this by mimicking native speakers or there's English Pronunciation in Use by Cambridge with explanations and exercises. You choose what works for you.

Conclusion

I've shared a few things that helped me sound better speaking English. What are your tips for improving your English accent?