Aunque mi amiga es modesta y simpática, todas sabemos que canta mejor que nosotras.

to be

Breakdown of Aunque mi amiga es modesta y simpática, todas sabemos que canta mejor que nosotras.

• mi: my
• cantar: to sing
• y: and

Questions & Answers about Aunque mi amiga es modesta y simpática, todas sabemos que canta mejor que nosotras.

Why is it aunque mi amiga es... and not aunque mi amiga sea...?

Because aunque can take either the indicative or the subjunctive, depending on how the speaker sees the information.

• Aunque + indicative: the speaker presents it as a real, known fact.
• Aunque + subjunctive: the speaker presents it as uncertain, hypothetical, or not important to the main point.

Here, mi amiga es modesta y simpática is treated as true and known, so es is natural.

• Aunque mi amiga es modesta... = even though my friend is modest...
• Aunque mi amiga sea modesta... = even if my friend is modest... / although she may be modest...

So in this sentence, es fits the intended meaning best.

Why are modesta and simpática feminine?

Because adjectives in Spanish usually agree with the noun they describe in gender and number.

Here the noun is mi amiga, which is:

• singular
• feminine

So the adjectives must also be singular feminine:

• modesto → modesta
• simpático → simpática

If the noun were masculine, you would get:

• mi amigo es modesto y simpático

Why is it mi amiga and not something like la mi amiga?