I don't know if this is a dumb question or what, but how do you go about writing in English as a non-native speaker? I've been wanting to write fic but I feel so limited by the language barrier. I constantly check for synonyms and connotations in meaning and every sentence is a struggle. Do you keep it simple and stick to vocabulary you feel comfortable with? Do you even write directly in English? Do you translate? I'm so lost.
This is not a dumb question at all! I have been writing fic in English for years and years, and I still struggle and have doubts - basically, everything you listed, I do that, too. It gets easier, though, because the more you learn, the more you can use the same structures and expressions all over again.
I apologize, this got overly long, so I put my ramblings under a cut. Everyone has a different approach to writing, so don’t this take too seriously - writing should be fun! I hope you’ll find this somewhat helpful, anon! :D
The one thing I’ve learned from every language teacher I’ve ever had: DO NOT TRANSLATE. Translating directly from your mother tongue to English just leads to tears (both from laughter and frustration). I write in English, and I try to think in English as much as I can, using structures, grammar, and words from that language. If that leads to simpler English, well…it will get better in time, the more you learn. If I hit a barrier that I just can’t breach, a sentence that just won’t form or a word that I can’t find, in extreme cases, I just mark it [word in Finnish] in bright red and leave it to be checked later, or even write [a whole sentence in Finnish] and come back to it later. Idioms are particularly awful - often, there’s just the perfect expression in your mother tongue but…apparently that’s not a thing in English. It was bitter to learn that not all idioms are translatable. Luckily, you can usually find something similar, if you hone your Google-skills.
I think the main thing for writing in English as a non-native is try to just read a lot. Awfully lot, and not just fan fiction. I use expressions I’ve learned from others, I use sentence structures I’ve seen others use, and I use words I’ve seen others use. Monkey see, monkey do, basically. But it’s important not to just copy word-for-word - copying won’t make you remember it the next time you need it. I check the expressions and learn what it really means, and sometimes overuse it in my excitement just because, “look mom, I learned a new thing!” :D From your message, it seems like you already do this by googling things, and not to worry, I do that too. Constantly. Usually, I just check how widely the expression is used - if it returns a million hits, I’ll go ahead and use it, but if it returns just a few, I’ll use something else. Simple as that. It’s also not a bad idea to keep a list of words and expressions that you know you’ll re-use in later fics - saves you time from researching the same thing again.
Often, the thing that I most struggle with is vocabulary in a very specific area - how do you find words that relate to forensic science, medicine, business, law, or, I don’t know, skeet shooting? Google is your best friend here, and if your fic doesn’t go too much into detail, readers will let it slide. If you can convey the basic idea using correct words, that’s usually enough. (Don’t be like me, who researches police procedures for two years for a fic that no one will read. Keep it simple. If only I learned this lesson myself…)
The best thing that any non-native writer can have is a native beta reader. Or any beta reader, really - another non-native will find errors that you can’t see, and a native will find errors that you didn’t even know were errors. Betas are one of the best things fandom culture ever came up with, and can save you from much humiliation. (If anyone wants to beta for me, hi! Always looking for a native beta reader.)
And, well, the main thing about writing is that you just write. The first draft is just that - the first draft. It’s gonna suck. It’s going to have holes in it, and it’s going to have sentences you need to replace and words that you need to check. Don’t worry about that. Just write! It’s easier to come back to something finished and edit it, rather than write one perfect sentence at a glacial pace.
Some links that might be helpful:
For checking idioms: English idioms, Idiomsite
For words and expressions in smut: The Ultimate Guide To Writing Smut Fic
For checking the meaning of a word: The Free Dictionary
For checking the rhythm of your writing: The Hemingway Editor (this is the best thing ever and I use it for all my writing)