01 · un before masculine
Tengo un hermano.
I have one brother.
Un before a masculine noun — the number is doing the same gender-matching job as an article.
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Count On Me
Say ages, prices, floors and dates with the right endings — out loud, without counting on your fingers.
Only three kinds of Spanish numbers change for gender. Uno shortens to un before a masculine noun and becomes una for feminine (tengo un hermano, hay una farmacia aquí — and the same inside bigger numbers: veintiún años, veintiuna páginas). The hundreds 200-900 agree too: doscientos estudiantes but doscientas personas. And the ordinals: primero and tercero clip to primer and tercer before masculine singular nouns (es mi primer día, el tercer examen), while primera and tercera never shorten. Every other number is invariable — and after tenth, everyday Spanish just uses cardinals: el piso doce, not el duodécimo piso.
Below: the phrases that put numbers to work in dates, times and prices, the number slang locals really use, the classic slips — and how you rehearse it by saying real quantities in a real conversation, not doing worksheet math.
The warm-up pack
The number agreements that come up mid-sentence — ages, prices, dates, floors — said out loud.
01 · un before masculine
Tengo un hermano.
I have one brother.
Un before a masculine noun — the number is doing the same gender-matching job as an article.
02 · una before feminine
Hay una farmacia aquí.
There's a pharmacy here.
Una in front of a feminine noun. Same word as "one," just doing double duty as a number and an article.
03 · Twenty-one, masculine
Tiene veintiún años.
He's twenty-one.
Veintiún drops its final -o before a masculine noun, exactly like un does. This is how you actually say someone's age.
04 · Twenty-one, feminine
Hay veintiuna páginas.
There are twenty-one pages.
Veintiuna keeps its -a for a feminine noun — the same un/una swap, just at twenty-one instead of one.
05 · Past ten, it stops changing
Hay diez sillas.
There are ten chairs.
Once you're past uno, most numbers stop changing entirely — diez is diez no matter what you're counting.
06 · When hundreds change too
Doscientas personas.
Two hundred people.
Answering "how many came?" Personas is feminine, so doscientos drops its -o for doscientas — hundreds agree just like uno does.
07 · First, the short way
Es mi primer día.
It's my first day.
Primero shortens to primer before a masculine singular noun — the same move as buen and mal.
08 · First, the long way
Es mi primera clase.
It's my first class.
Feminine primera never shortens — it's only the masculine form that drops a letter.
09 · Third shortens too
El tercer examen es difícil.
The third exam is hard.
Tercero follows primero's lead — tercer before a masculine noun, no exceptions.
10 · Telling the time
Son las tres y media.
It's three thirty.
Time always takes the feminine las — you're really saying "the three thirty," with hours implied as feminine.
11 · The one o'clock exception
Es la una de la tarde.
It's one in the afternoon.
Only one o'clock uses es la instead of son las — because una is singular, everything else is plural.
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Ten-minute spoken lessons. A teacher who answers back — and gently fixes what you got wrong.
First 10 lessons freeandbefluent.com/spanish/count-on-meRegional Spanish
Textbooks teach one word. Locals use several — pick your region's and stay consistent.
| English | Mexico | Argentina |
|---|---|---|
| loads of (vague big number) | un chorro / un buen | una banda |
| money (slang) | una lana / un varo | lucas (thousands of pesos) |
| …and a bit (after a number) | quinientos y pico | las tres y pico |
Watch out
The part no drill site can do
Carla
Your grammar teacher for this pack
No worksheets, no number drills. In the Count On Me lessons you talk, and Carla makes the numbers yours: she asks your address and which floor you live on, so el piso plus a number comes out naturally; she lines up four mixed nouns and you put un or una in front of each — un café, una mesa, un libro, una llave — out loud, no pausing to translate. Then it's your birthday and one date you're looking forward to: el quince de marzo, said like you've said it a hundred times.
Blank mid-sentence and nothing bad happens — she waits. That's the practice, without unnecessary judgement.
Finish the 4 lessons and Count On Me is yours — earned, not given.
First 10 lessons free · 10-minute spoken lessons · your AI coaching team remembers you
Quick answers
Before a masculine singular noun: tengo un hermano, never uno hermano. For feminine nouns it's una (hay una farmacia aquí), and the rule repeats inside larger numbers: veintiún años, veintiuna páginas.
It depends on the noun: doscientos estudiantes (masculine) but doscientas personas (feminine). Only the hundreds from 200 to 900 do this — quinientos euros, trescientas páginas — everything else stays fixed.
Primer is the clipped form used only before a masculine singular noun: es mi primer día, el primer piso. Elsewhere it stays full — el primero de enero — and the feminine never shortens: es mi primera clase.
Plain cardinal numbers: el quince de marzo (March 15th). The one exception is the first of the month, which keeps the ordinal: el primero de enero. Years read as one long number: en el año dos mil veintiséis.
Son las tres y media (it's 3:30) — but one o'clock goes singular: es la una de la tarde. For "a little past", locals say y pico: son las tres y pico.