As a new learner there are 3 important Portuguese contractions that you need to know.
Brazilians use these all time in everyday speech:
Em – in, on or at
em + o = no
em + a = na
Of course, there are PLURAL versions also. But let's keep it simple. You can get by fine without the plurals until you are already making your own sentences.
Notice that the no & na are saying in the. It used to really throw me saying no when we are so used to no meaning no.
How about saying in a or, in an?
em + um = num
em + uma = numa
De – of or from the
de + o = do
de + a = da
A – at or to the
a + o = ao
a + a = à
From the video learning course, INTENSIVO.