Lo + adjective in Spanish is a really useful way to say “the …. thing”. This is a very typical Spanish way of speaking, making you sound more like a native speaker. Also, if you are studying for GCSE, A2 or A-level Spanish if you can use this type of more difficult structure, you will gain higher marks.
Here are some examples of ways to use this expression:
Lo importante es que …: The important thing is that …
Lo bueno es que …: The good thing is that …
Lo malo es que …: The bad thing is that …
Lo mejor de mi ciudad es que …: The best thing about my city is that …
Lo peor del hotel era que …: The worst thing about the hotel was that …
When “lo + adjective” is followed by “que” this puts added emphasis on the adjective:
El libro demuestra lo duro que era la vida durante aquella época.
The books shows how hard life was at that time.
Yo pensaba en lo útil que es este programa.
I was thinking how useful this program is.
Note how in the first sentence the adjective “duro” is in the masculine form even though it is referring to a feminine noun “la vida”. This is because “lo duro” actually means “the hard thing”, therefore this is a phrase with no gender.
However, it is also common in Spanish to make the adjective after “lo” agree with what it is referring to, but still keeping “lo” rather than “la” or “los” / “las”.
No podíamos creer lo guapa que ella estaba aquel día.
Nobody could believe how pretty she looked that day.
No entienden lo útiles que son estos libros.
They don’t understand how useful these books are.
Recuerdo lo tontos que éramos entonces.
I remember how silly we were then.
No puedo creer lo baratas que son las bebidas en este bar.
I can’t believe how cheap the drinks are in this bar.