As you know, children are likely to choke on food as they grow and learn how to chew their food properly. However, for children under 4, this skill might not be fully developed yet and some food might be too big for their wind pipe. At that age, children don’t yet have their molars to grind and chew on food.
Things to avoid serving:
Popcorn, Whole nuts, peanut butter on a spoon, hardened candy or gum, and marshmallow
Food to cut lengthwise in halves or quarters:
grapes, cherries, blueberries, cherry tomatoes, sausages, apples, raw carrots, meat and cheese.
Apples should be chopped or grated and remove the skin as it can stick in their throat. Raw carrots should be cut in no more than 1 cm. Meat and cheese chunks should be cut in small pieces or mushed.
And remember food that are smaller than the windpipe or soft are fine.