Learn Turkish: Biz beraber yürüyoruz. - We are walking together.

The dictionary form "to walk" is yürümek. We drop -mek to get the stem yürü-. Then we add the present continuous tense marker to get yürüyor. Finally, we attach the personal suffix for "we", which is -uz.

Why is the "we" ending -uz here instead of -iz?

It is because of vowel harmony! The personal suffix attaches directly to the present continuous marker -yor. Because o is the last vowel in -yor, the "we" suffix must harmonize with it. This means the "we" ending for this tense will always be -uz.

Since yürüyoruz already means "we are walking", do I have to use the word Biz?

Not at all. Because the -uz ending clearly shows that the subject is "we", dropping Biz is completely normal in everyday Turkish. Keeping it here just adds a little extra emphasis to the fact that we are the ones walking.

Why is beraber (together) placed right before the verb?

In Turkish, verbs generally go at the very end of the sentence. Words that describe how you do the action, like beraber, are usually placed right in front of the verb they describe.