We've written about common Portuguese contractions before, but in this post I want to give some more examples using just em + o/a and the contractions of em + um/uma. This is one of the hardest things for beginners to get the hang of. It took me years to feel confident using contractions. I think that if gender weren't involved they would be easy to pick up.
Let's review the most important Portuguese contractions.
In my head I would always think of the word "no". It eventually passed.
Brazilians absolutely love to place an no or na in front of everything. Even when it's not clearly in the or on the. Like this:
Na praia? Literally this translates to Let's go on the beach. Seems strange but that's the way it's said. You could have of course said Vamos à praia or, Vamos para a praia.
Be careful. For Brazilians, o shopping is not a verb, it's a noun. Shopping = the shopping center (mall). Another correct way of saying this would be Vamos ao shopping or, Vamos para o shopping.
Short for, Eu fui na casa da Alice. You would be fine saying it like this: Eu vou para a casa da Alice.
The no & na are of course the contractions of em + o & em + a respectively. These are literally, just in the or on the. But what about saying in a or on a?
em + um = num
em + uma = numa
There are plurals for all of these. I don't think it's worth worrying about the plurals until you are fine with the singular. Brazilians say the plurals so fast that it's tough to discern from the singular. In other words, you can get away with using the singular 90% of the time - even when in plural contexts. No one will notice 😉
Listen to this example of NUMA in context: