This is a version of 20 questions, though there doesn't have to be a limit on the number of questions asked. One person thinks of an animal. Everyone else takes turns asking questions to try to identify what the animal is. The winner is the person who correctly guesses the animal. The winner then gets to pick the next animal. Another option is to simply take turns coming up with an animal.
Apples to Apples is a party game in which red apple cards have nouns and green apple cards have adjectives. Each person gets a turn to play a green apple card. All the other players have to select the red apple card that they think most closely fits the word on the green apple. The person who played the green apple card then gets to choose which red apple card he or she likes the best. The person who put that card in gets the green apple card. You need five green apple cards to win. While fourth-graders could probably play the full version of Apples to Apples, the junior version will have more words that they recognize and popular culture references that are relevant to them.
This activity is a mutual story-telling game. Have one person start a story by speaking a single sentence. The next person continues the story with a single sentence. Continue taking turns providing sentences until the story has been brought to a conclusion. Encourage your fourth-grader to use strong verbs and interesting adjectives.
One person comes up with a topic, such as "Giraffes" or "Spaghetti." The person to the right then has 1 minute to come up with a speech. He or she must then speak on that topic for 1 minute without pausing or saying "um" or "uh." The play continues until everyone has taken a turn.
One player comes up with a word that has at least five letters in it. Then everyone has 1 minute to create a sentence in which the words start with the letters of the word, in order. For example, if the word was "monkey," a sample sentence might be "My Old Nanny Knits Every Year."
One person says a word. The next person must say another word that begins with the letter that ends the previous word. For example, the first person might say "Pizza." The next person could say "aardvark." The third person could then say "king." Continue taking turns. Do not repeat any words that were said before and try to keep the pace of the game fairly quick so that there is never more than 5 seconds between words being spoken.