Learn Hardcore Latin: Tu multum scribis.

In Latin, the verb ending -is (from scribis) indeed shows that the subject is "you" (singular). The pronoun tu (meaning "you") can be used for emphasis or clarity. You might see tu scribis in contexts where the speaker really wants to highlight you as the writer, but you can also simply say multum scribis without tu and still be correct.

Is "scribis" related to the Latin infinitive form "scribere"?

Yes. Scribere is the infinitive form meaning "to write", and scribis is the second-person singular present active indicative form. In other words, scribis means "you write" right now, or as an ongoing action.

What part of speech is "multum"?

Multum here functions like an adverb meaning "much" or "a lot". It describes the extent or frequency of the writing. Latin can use multum in various ways, but in this sentence, it tells us how much you are writing.

Can we change the order of the words? For example, can we say "Tu scribis multum"?

Yes, Latin word order can be relatively flexible. You could place multum before or after scribis. Saying Tu scribis multum might slightly shift the emphasis, but both Tu multum scribis and are grammatically correct and convey the same basic idea: