Sunday, February 21, 2010

Morphology: derivation and inflection

Morphology is the study of the structure of words, and the processes by which they're produced. Within morphology, we talk about (among other things), derivation and inflection. It took a little bit of reading for me to understand the difference between the two, so hopefully I can explain it to you.

Derivation is when new words, typically of a different part of speech, are produced from existing words. In English, we have quite a few affixes to change a word's the category, and interestingly, they're not very regular. To make something black, you blacken it, but to make something hollow, you hollow it. In Calvin and Hobbes, Calvin uses verb as a verb that means "turn something into a verb". To make something into a product, you can (recently) productize it. What word can you use to make something blue? Have you ever bluified something?

Inflection is rather simpler. It takes a base form of a word and encodes some extra meaning in it -- what extra meaning varies by language, but it's often things like plurality or gender. Typically the language requires that words be inflected properly.

Languages differ pretty broadly how much information a given inflected word carries. For example, a verb in Spanish carries more bits than one in English, so in Spanish ("Hablo castellano.") you often don't have to specify the subject of a verb, because its inflection makes it clear who you're talking about [0]. Some languages encode quite a lot of information in one verb: maybe its object, the whole tense (so no need for modal verbs like "would" or "haber"), the genders of all the participants, maybe even how the speaker came to know the information in question [1].

I have a whole lot of linguistics to learn. It's interesting being around a department where a lot of the people are linguists by background, when I've only put so much time and attention into it. So you'll get more posts like this, rest assured.

[0] This feature, of not having to specify pronouns, is called being a pro-drop language. Some languages can drop more pronouns than Spanish!

[1] This feature, grammatical evidentiality, is extremely awesome, and we need to adopt it in English.


Sunday, February 07, 2010

drawing trees with LaTeX

So, whatever you think about producing documents with LaTeX (personally, I'm pretty ambivalent, for reasons that I may go into later), if you want to draw parse trees with it, there's a nice package to do that: qtree.

Installing packages from CTAN manually looks hard.

If you're on Ubuntu/Debian, though, you just need to install these two packages: texlive-humanities, texlive-pictures.

qtree itself is in texlive-humanities, but it depends on a package, pict2e, that's only in texlive-pictures, so you have to install them both or it won't work.

And then you can draw some trees just by specifying the bracketing of the phrases (see the qtree docs for exactly how).