There are four cards in a set (or family) and students need to collect all four of the same card, to win one point. All cards are dealt out as equally as possible and player one asks for a card matching one they are already holding. The player must already hold one of that family. Obviously this would be in the TL of the classroom, but an example below.
Player one "John, I need Boris the baker. Do you have Boris the baker?"
If John has any of those cards he must hand them over to player one. Player one then gets to ask someone else the same question. If the next person asked again has a card, they hand it over. If they do not, then it is their turn to ask someone of their choice about something they need.
As players form sets of 4 they place them face down on the table and the winner is the player with the most sets.
You can download the ones I have already made below.
German jobs
Spanish animals
Spanish quantities
This is very similar, but players only start with 5 cards and the spare cards are placed in the centre. If the person asked does not hold any of the cards in question, then they tell the other to "Go fish" and the player must pick up a card. If the player happens to draw a card of the type asked for, they must show it to the other players and then have another turn. However, if the card is different then it becomes the next player's turn. It is the player who said "Go fish" who goes next.