This achievement requires you to earn 1000 points by contributing helpful guesses throughout the game.
Open up two tabs in Google Chrome using the following method:
Click on the person image in the very top right of your browser. Go all the way down to "manage people" and click on it, then click on "add person" in the bottom right corner. Once you click it, click an image for them then click "save" in the bottom right corner. This will open a new pop up window for that person.
Join the game lobby with both tabs and start the game. Select your password and sentence for both accounts. When you are able to start guessing, have the tab that is guessing type in 10 random guesses. The tab who is supposed to be giving the clues can create garbage sentences until you get a selection where you can choose phrases like "it's not like", "it's similar to", etc. on the left column, and the players guesses on the right column. When this pops up, pick any phrase from the left column and select three of the players guesses in the right column. This will give the other player 300 points. Just keep repeating this method until the guessing player gets 1000 points, and the achievement will pop straight away.
Note that you can only select 3 of the players guesses for one phrase, so you'll need to enter that phrase just under 4 times. It also does not need to be done in one round, as I spread it out over the two, but it does need to be with one tab.