Proverbs are quite common in spoken English. We do not normally put them in

Proverbs are quite common in spoken English. We do not normally put them in a composition or letter. Sometimes it is helpful if you know what common proverbs mean. For example, "Once bitten, twice shy". If a dog bites me, I shall be twice as careful in future when I see it. This proverb is also used to apply to many things and not only to dogs. If you have been cheated at a shop, you will not go to the same shop again.
    "A bird in the hand is worth two in the bush." If I am a hunter, trying to catch birds, it is better to catch one bird than to see two birds in a bush but not be able to catch them. Thus this means that what you have already got is better than the chance of being able to get something bigger in future.