To express accompaniment, "I am going with my friend" vs "My friend and I are going", use 跟, "to follow" or "with" and 一起, "together".
A + 跟 + B + 一起 + Verb + [Object]
The mode of transportation is a Verb-Object phrase that comes before the main verb. We already learned 坐, "to sit", this character is also used as "to ride", as in 坐車. In this lesson we have the new vocabulary item 走 [zǒu] "to walk". This is usually expressed with by the verb phrase 走路 [zǒu lù] "walk roads", but the 路 can be left out. We will learn that in lesson 21 when we will also learn how to drive a vehicle. Now we have two means of conveyance to use in the following pattern.
Conveyance + Verb + [Object]
This instrument is also a Verb-Object expression using 用 and an object as the tool for accomplishing the following action.
用 Instrument + Verb + [Object]
Subject + Time + Accompaniment + Origin + Conveyance + Action
Time + Subject + Place + Benefactor + Instrument + Action
Subject + Time + Accompaniment + Conveyance + Action + Purpose