Hello @ruzz ^_^
Almost everyone of us naman ay nagkakamali pa sa grammar...
So here are some tips:
First learn the basics: Like the uses of are, is , has , and have
And also the tenses. Mag-research and pag-aralan muna yan. Then I-master mo.
Next: If you're having a difficulty in composing a paragraph, try making simple sentences first. Gumamit ka muna ng isang topic at mag-focus dun. Gumawa ka ng maraming sentences then after that pagsama-samahin mo yung may same thoughts tsaka pagsunod-sunodin mo hanggang sa makabuo ka ng paragraph.
Gumawa ka ng maraming paragraph hanggang masanay ka na. Try writing different genres like romance, horror, thriller, comedy etc.
Soon magiging magaling ka na din sa paggawa ng paragraph at magiging maayos na ang grammar mo. And who knows baka maging isang magaling na writer ka din?
If you failed at first don't give up. Failure will lead us to success. So just keep on writing and trying again.