How to distinguish the left and right of couplets by dividing them into upper and lower couplets

You can distinguish horizontal links by looking at their left and right sides.

1, the writing method of the horizontal couplet is from left to right. Then couplet left couplet, right couplet.

2. The writing method of horizontal couplet is from right to left. Then couplet right couplet, left couplet.

Part I is the last word of part I. Generally speaking, it means three or four tones, and the last word is flat tone, which is the bottom line, usually one or two tones.