Here are 3 tips that should help you perfect your Portuguese pronunciation of "Nós estamos aqui":

• Break "garrafa" down into sounds: say it out loud and exaggerate the sounds until you can consistently produce them.
• Record yourself saying "garrafa" in full sentences, then watch yourself and listen. You'll be able to mark your mistakes quite easily.
• Look up tutorials on Youtube on how to pronounce "garrafa".

To further improve Portuguese pronunciation, we suggest you do the following:

• Focus on one accent: Brazilian Portuguese sounds completely different that European Portuguese. So think about where you will be working, studying or traveling and make your choice accordingly.
• Learn to use contractions: in portuguese, words flow together to make one sound. Pronounce everything before a comma or full-stop as if it was one word.
• Guttural 'R' v.s. rolling 'R': Guttural R applies to initial or ending 'r' ( Rio [xˈiu], cobrador[kobɾadˈox]), double 'r' ( garrafa[ɡaxˈafɐ]) or at the end of a syllable ( corpo [kˈɔxpu]). Any other 'r' will be a rolling 'r'.brincando [bɾĩkˈɐ̃du]
• Subscribe to 1 or more Portuguese teaching channels on Youtube: it's free and it covers the core topics of the Portuguese language. Check out Gavin and PortuguesePod101 channels to name just a few.