Feeling undermined at work - advice please

[MagicMittens]

Can anyone advise me on this situation at work. I don't really know how to handle it or whether I'm being unreasonable to feel like this. Sorry if this is a bit rambly, it's hard to explain it succinctly.

I work as an in-house translator at a large institution. There's someone else in the institution who has always given my the impression that he thinks I'm a bit stupid and bad at my job. It's hard to pin this down with concrete examples, so I don't really have anything to complain about, it's just a vibe I get from him.

He recently sent me a document to translate from the department he works in. It was an updated version of an older document and he sent me a link to a translation of the previous version and said I'd need to update the old translation and also give it a thorough overhaul because it was quite poor. I got a bit of a shock because I assumed it was my translation, but I checked it and it was from before I was hired. I sent back a joking sort of message saying oh I was a bit worried there, I thought my work wasn't up to scratch. He replied saying sorry to worry you, of course that couldn't have come from you.

Anyway I turned in my translation and I've just had a reply from him saying thanks for the translation, here are my revisions. He's changed SO much, it's quite obvious he thought it was really bad work. I felt like shit when I saw it. On the surface he's been polite to me, but he clearly thinks I'm absolutely incompetent. Most of the changes are just petty rephrasing and I'm not saying his version is any worse but I honestly can't see why it's better in most cases. He's also changed some key vocabulary.

Something that is relevant is that we are both native English speakers, but he's from the US and I'm from the UK. I think a lot of the terms I use that he obviously thinks are ridiculous are just down to the fact that we come from different countries. The institution obviously knew I was British when they hired me and told me they were happy for me to use British English and base my vocabulary choices on the systems I was familiar with from the UK.

Part of my job description is also to try to maintain consistency in the English vocabulary used in the official texts so by making the executive decision to change those key terms he's put me in quite a tricky position, because there are umpteen other texts that use these words.

To be clear, of course I'm happy to accept corrections and constructive criticism but almost everyone else I work with is extremely happy with my work and I get a lot of positive feedback generally. I'm now questioning whether I really am any good at my job at all, maybe I'm a complete fucking idiot.

Should I bring this whole thing up with my manager or what should I do?

Does your organisation have a house style sheet? Do you use UK or US English for your website, internal comms, etc? If you had a style sheet then you could point to it for your style decisions.

Who is the audience for the translated document? Are they in the UK or USA?

Is this guy senior to you? If not, could you change his amends back to your original? Or flag up contentious ones and say, eg, 'My style decision here came from New Hart's Rules, the main style guide for the UK - what have you based your change on'?

Also make a list of all key terms that need to be kept -us change the back and quote other docs that they appear in.

I would also not jump to conclusions - don't email him like you did, worrying that your work wasn't good enough. Why do you think he thinks your word choices are 'ridiculous'? They're not! Be more assertive. You get good feedback from everyone else so if only this guy has a problem with you, the problem probably lies with him...

Is he older? What do other staff think of him? Is he just awkward with you?

Sorry, that should say

Also make a list of all key terms that need to be kept - I'd change them back and quote other docs that they appear in.

The audience is international. He's definitely in a more senior position than me but he's not really above me per se as he works in an entirely different unit. He is older than me and I don't know how he is with others as I never usually work with them. He's already gone over my head and sent on his version to be published on the website so he wasn't suggesting changes, he was letting me know ('for my convenience' apparently). It's the way there was no discussion, no real professional courtesy.

The institution doesn't have a style guide for English unfortunately and are usually fairly easy going about AmE vs BrE - in a lot of situations people are allowed to simply use the English they are most familiar with. But there are some texts that are more formal and official and these are supposed to be consistent.

Quite beside the issue with the key terms, most of the changes he's made are things that (I believe) could legitimately be phrased in more than one way, but he seems to have changed just for the sake of it. Honestly this is what has actually upset me because it was almost every sentence that was edited, as if my work was of a really low standard. I felt like asking him why he didn't just do it himself. I am trying to tell myself that it was not bad work, but it's really shaken my confidence.

Yes, I probably do need to be more assertive, thank you for your advice. I think part of the practical problem is that there is no official clarity on who is responsible for determining English terminology. But this mainly affected me because I felt so disrespected.

Something that is relevant is that we are both native English speakers, but he's from the US and I'm from the UK.
Does he speak the language you're translating from? Or is he just seeing your translation and 'editing' that?

Part of my job description is also to try to maintain consistency in the English vocabulary used in the official texts so by making the executive decision to change those key terms he's put me in quite a tricky position, because there are umpteen other texts that use these words.
So this is why you need a style sheet that contains, along other things, a list of your company's key words. For all your branding and comms to be consistent, these should remain the same.

He's already gone over my head and sent on his version to be published on the website so he wasn't suggesting changes, he was letting me know ('for my convenience' apparently). It's the way there was no discussion, no real professional courtesy.
I'd probably bring this up with my manager, if I were you. What usually happens? Do you discuss changes to translated docs so that everyone is happy, or do people generally go with your translations?

If he thinks you've done a bad job and wants you to improve, he's not going about it the right way.

Quite beside the issue with the key terms, most of the changes he's made are things that (I believe) could legitimately be phrased in more than one way, but he seems to have changed just for the sake of it. Honestly this is what has actually upset me because it was almost every sentence that was edited, as if my work was of a really low standard.
Could you arrange a meeting with him and go through your translation then his changes and ask him to explain why he made each one? Then you would find out if he was just changing things for the hell of it or whether he had genuine reasons for doing so.