Words like schwer

[Herger]

I am currently learning German with Duolingo. I came across the following:

der Junge ist schwer.

How on Earth can a person tell if the sentence is supposed to mean:

"The boy is heavy" or "The boy is difficult"?

The concepts aren't even close. I have noticed other examples like this as well.

[Kektheman]

In real life, you would figure it out by the context. The sentences around this particular one would tell you what the correct meaning of the world would be. schwer is just a homonym, like many English words. For instance glass, key, spring, match, etc.

[Skyfox]

Do you happen to have the context? Because now I'm curious. I've mainly heard it used to mean difficult, but that's probably because I was around college students while I was in Germany. That said, Kektheman is totally right, it can mean either in any given situation.

[宇崎ちゃん]

A lot of languages tend to have one word with multiple meanings.
You can think of "to see", which can mean "to look at somebody" or "to understand what you mean".
Or regionally "rooting": it means "to cheer for" in the USA, but in Australia it means "to have sex with".

German isn't anything different, "schwer" is indeed "difficult" and "heavy".
And as with "to see" in English, the full context is really important.

It's simply a fact you will never learn in apps like Duolingo, Rosetta Stone, Pimslur, etc.

[Sailor Cat]

I'm German and I've never heard "Der Junge ist schwer" in the sense of "The boy is difficult." You would rather say: "Der Junge ist schwer erziehbar", or something like that.

So I'm sure it means "the boy is heavy". But as the others say: Normally you'd know that from the context.