The internet is awash in ads that make it harder to see what you want, but that doesn’t mean you can always tell them apart. 

The ads are often more subtle than you’d expect, and the only way to truly see them is to look for them.

A new study, by the UK-based online advertising platform AdWords, suggests you can spot them by looking for the type of text that appears in the ad: text that tells you whether it’s from a reputable source or from a fake source.

The study, titled ‘The Great Lie: How to spot online ads,’ was conducted over the course of two months, from January and February, 2017, and looked at more than 5,000 ad impressions from both sides of the Atlantic.

It found that ad impressions were a little more subtle in the United Kingdom than in the US, where users were more likely to see ads that said, ‘Please sign in to see our advertising.’

This may have been because UK users are more likely than US users to know what ads are real.

The researchers also found that people who clicked on an ad from a genuine source would see a higher number of ads from reputable sources, and that they would click on ads from a counterfeit source if they were presented with a genuine one.

AdWords said the research suggests that you should never trust any ad you see, but it did warn that you shouldn’t rely on this information alone to spot ads.’

Your best bet is to try to identify these types of ads by looking at the text,’ it said.

Websites that use Google Ads can now tell you whether an ad you’re about to see is from a trustworthy source or a fake one, as well as whether they’re genuine or not.