Learn Hardcore Dutch: Anna ziet een druppel water op haar jas.

In Dutch, when you use a measure word (like druppel = “drop”) followed by a substance, you normally don’t repeat the indefinite article. een druppel water literally means “a drop of water.” You wouldn’t say een druppel een water, just like in English you don’t say “a drop a water.”

What gender is druppel and how do I know which article to use?

druppel is a de-word (common gender), so it takes de in the definite form: de druppel. For the indefinite you always use een druppel regardless of gender.

Can I say een waterdruppel instead of een druppel water?

Yes, you can form a compound noun waterdruppel (“water drop”), which is also common. In that case you treat waterdruppel as one word and a de-noun: een waterdruppel, de waterdruppel.

Why is water not plural? Wouldn’t it be wateren?

water is an uncountable noun in Dutch (just like in English), so it doesn’t get a plural -en. The drop itself is countable (druppels), but the substance water remains singular.

What does op mean in op haar jas, and could I use aan or in instead?

op means “on” (on top of).

aan would be “at” or “on” in the sense of “attached to” (e.g. een bel aan de deur = “a bell on the door”).
in is “in” (inside).
Since the water drop is sitting on the surface, op haar jas is correct.

Why is haar used for “her” and how does it differ from zijn?

haar is the possessive pronoun for feminine or neuter nouns when the owner is female: haar jas = “her coat.” zijn jas would mean “his coat.” The form doesn’t change with the gender of jas; it changes with the owner’s gender.

Why is the word order Anna ziet een druppel water op haar jas and not Anna ziet op haar jas een druppel water?

Dutch allows both orders, but the most neutral, unmarked order is Subject–Verb–Object–Adverbial:

Anna (subject)
ziet (verb)
een druppel water (object)
op haar jas (prepositional phrase/adverbial)
If you move op haar jas before the object, you’re just changing emphasis: it’s still correct but less common in neutral statements.

What tense is ziet, and how do you conjugate zien in the present?

ziet is the third-person singular present tense of zien (“to see”). Conjugation in present tense:

ik zie
jij ziet (or zie jij in questions)
hij/zij/het ziet
wij/jullie/zij zien

Could I use a diminutive like druppeltje? What changes then?

Yes. druppeltje is the diminutive of druppel, adding a sense of smallness or endearment: een druppeltje water = “a little drop of water.” It remains a neuter noun in the diminutive (het druppeltje), but since you’re using an indefinite article, you still say een druppeltje.