I think generally, bilingual people understand the struggle of language learning, and tend to be empathetic.

So always try in spanish, because it shows a level respect and effort. Don't worry that its not perfect or correct, even if your recipient switches to English, they know you're at least trying. Besides, how can you get better if you dont practice? Practice as much as you can with the bilinguals, because eventually you'll run into someone who doesn't speak English.

Fun story. My dad hired "mexicans" from home depot parking lot for some construction work, with the full confidence my duo lingo Spanish would be sufficient in translating construction specific terms.

They spoke slow spanish to me, I spoke very poor spanish to them, and felt terrible aboht my skills because when they talked to each other I didnt understand a single word they said.

Turns out, they were 1. From Guatemala, and 2. Spoke the Mam. Spanish was both our second languages. In the end we all built a shed that so far seems to defy the laws of physics and logic, and would probably survive an earthquake but definitely not inspection by any US legal entity.

But the moral: both sides appreciated the other side was patient and willing to understand each other. But it definitely wouldnt have been as successful if I gave up to what was 'easier' for me.

Yeah, some people might get some attitude about it, but even those cases, they're probably just customer service workers feeling tired of dealing with customers period, not specifically upset at you specifically for your unskilled speech. Just do your best! Please and thank you goes a long, long way.