Portuguese can seem like a tough language of origin from which to spell a word. How is one supposed to be able to figure out ridiculous tongue twisters like caixinha or cavaquinho or chocalho? It really can be difficult. However, it's only exceedingly difficult if you don't understand Portuguese spelling patterns; in fact, Portuguese has become one of my favorite languages to spell words from because of its unique yet more or less consistent patterns. Let's take a look at Portuguese via the three aforementioned tongue twisters (that all happen to be musical instruments).
Caixinha: a box rattle used in Brazilian dance orchestras. This is my favorite Portuguese word of all. There's just something about the sound of it and the way the letters go together that makes it great. The \k\ sound, of course, is spelled with a c--this is the norm in Portuguese words, as Portuguese is a Romance language. Romance languages are derived from Latin, and Latin rarely if ever uses the letter k, and as a result, the other Romance languages behave similarly. The rest of the word follows typical Portuguese patterns as well, including the x used to spell \sh\ and the characteristic h used to make the \y\ sound (this occurs mostly after the letters l and n in Portuguese words).
Cavaquinho: a Brazilian stringed musical instrument somewhat smaller than a ukulele. Besides the \y\ pattern again visible in this word, there are two notable things about cavaquinho. Firstly, there's the qu being used to spell \k\. This does deviate from my previous observation that c is most commonly used--qu is used before i and e, and c is used in all other situations, as a c before an i or an e would be pronounced \s\. The other thing worth noting is the fact that the word ends in an o--for words ending in the \ü\ sound that come from Portuguese, this is the typical ending.
Chocalho: a Brazilian rattle commonly consisting of a gourd with its dried seeds inside. This word is basically a repeat of previously-discussed patterns (for example, the \ü\ sound being spelled with an o or the \y\ sound being spelled with an h). The only other thing of note is that it exemplifies the other option besides x for spelling the \sh\ sound in Portuguese--ch. The use of x vs. ch is very context-dependent, and it's best to just learn some Portuguese words with that sound in order to get a feel for when to use which.
Portuguese, while difficult, gives us some tremendously fun words. It really only takes a little bit of work with the language's spelling patterns to start having a great time with Portuguese!