Learn Portuguese (Portugal): É meio-dia e nós estamos cansados.

When telling time, we use the verb ser (to be) and match it to the number of hours. Since meio-dia (noon) is a singular concept (just like one o'clock), we use the singular form É. For plural hours, like two o'clock, you would switch to the plural form São (São duas horas).

Why is it meio-dia with an 'o', but I sometimes see meia when telling time?

The word meio means "half" and must match the gender of the word it goes with. Because dia (day) is a masculine word, we use meio. You will see the feminine meia when talking about midnight (meia-noite) or the half-hour mark (like uma e meia), because both noite (night) and hora (hour) are feminine.

We used É for the time, but estamos for being tired. Why use two different verbs for 'to be' in the same sentence?

Portuguese has two verbs for "to be". We use ser (here as É) for permanent facts like the time, dates, and who you are. We use estar (here as estamos) for temporary states or conditions, like how you are feeling physically or emotionally right now (cansados).

If a group of women is speaking, does the word change?