Learn Farsi: خانواده‌مان خیلی بزرگ است.

The word خانواده ends in a silent 'h' (ه), which sounds like 'e'. Because of this vowel sound, we attach the ending -mân (our) instead of the usual -emân. In typing, a special 'half-space' character is often used before the suffix to keep the shape of the 'h' intact, making it look like خانواده‌مان.

Why does the ending for 'our' not have an 'e' sound at the beginning here?

For most words ending in a consonant, the suffix is -emân (like ketâb-emân for 'our book'). But since خانواده already ends in an 'e' vowel sound, adding another 'e' would be hard to say. We drop the extra 'e' and just pronounce it 'khânevâdeh-mân'.

Could I say خانواده ما instead of using the attached ending?

Absolutely! You can use the separate pronoun ما (we/us) linked by the 'ye' sound, giving you خانواده ما (khânevâdeh-ye mâ). Both mean 'our family' and are perfectly correct, but the attached ending -mân is very common in everyday speech.

Is the verb است (is) always placed at the very end of the sentence?

Yes! Farsi places verbs at the end of the sentence. In simple descriptive sentences like this one, the 'to be' verb است (ast) will almost always be the very last word.