Learn Spanish (Latin America): Ella está tejiendo una bufanda azul.

Ella está tejiendo uses the present continuous tense (estar + the -iendo ending) to emphasize that she is actively knitting right at this very moment. You could also say Ella teje una bufanda azul for "She is knitting a blue scarf," but the continuous form adds that extra "right now" emphasis.

How is the word tejiendo formed?

It comes from the regular verb tejer (to knit or weave). To make the Spanish equivalent of an "-ing" word (called a gerund) for an -er or -ir verb, you simply drop the ending and add -iendo.

Why does azul come after bufanda?

In Spanish, descriptive adjectives like colors almost always come after the noun they describe. So, instead of "blue scarf", the word order is literally "scarf blue" (bufanda azul).

Since bufanda is feminine, shouldn't the adjective azul change to match it?