I will try to answer this question even though lyric writing is not my forte. First to get this out of the way: Lyrics are important. Don't underestimate how you can totally ruin a good song my putting in lousy lyrics.
Second, lyrics can communicate something important. Or they can evoke powerful emotions. Or they can be funny. Or they can simply sound good, ie nobody knows that "kick out the jams mother lovelovelove" means but nobody can deny that it sounds great. Substandard lyrics fail to achieve any of these objectives. There must be some content.
It would really help if you had at least an "O" level in literature. Or if you read a lot of books, and you read and write often. Sorry, but this is the one of the few areas where intelligence and learning is actually useful. If you don't know how to do practical criticism, chances are you won't be good at writing because you can't tell what makes a lyric good.
Other than reading a lot of books, reviews of CDs, especially the in depth ones, are very useful. Because the reviewer will often talk more about the words than the music. (Natural since music is so hard to write about.) And they will point out a few really good lines that stand out, you can learn a lot that way. Another way to learn good lyric writing is to read really good lyrics. Morrissey and the Smiths are the absolute masters. Beatles are good lyric writers: what they do is very deceptively simple, but it is very hard to write simple lyrics and not make them sound like schlock. Forget about Bob Dylan because he is too cheem and only people with English degrees will appreciate him.
Not going to say too much about lyric writing in general but there are so many books out there and you can go read them yourself.
OK, after these general remarks, I can give you 2 artists who write very good lyrics in spite of their not mastering standard English. They are Bob Marley and ABBA. About Bob Marley, here are the lyrics of “Redemption Song”.
http://www.sing365.com/music/lyric....s-bob-marley/326f5783c5461a6048256945000e6461
The lyrics are so good that the grammar mistakes do not detract from the gravity of the lyrics – you will never laugh at his mistakes. Of course, Bob Marley was an extremely inspired man as he penned those words: he knew he was going to die.
ABBA, of course, wrote “Dancing Queen”, “Knowing Me Knowing You” and “The Day Before You Came”. All of them demonstrating mastery of lyric writing without mastery of English.
Counter-intuitively, I’m going to tell you that you shouldn’t break any grammar rules on purpose. ABBA and Bob Marley write lyrics in exactly the way they speak English. And that is a useful guideline. One good method of writing lyrics is you should always listen out for good lyrics. Every time somebody says a line or a phrase that sounds like a good lyric, write it down in your scrap book. Collect enough of these, and you have a lot of material to write songs with. Unless you are an expert, you should never fake the way that other people speak. If you are writing in Singlish because you just said something in Singlish, that is fine. So don’t write like a fake Englishman, or don’t fakely exaggerate your Singlish. Just write something the way you would have said it if you were speaking naturally. In verbatim.