As children progress through the discovery of language in their first three years, there are predictable patterns in the emergence and development of many of the language they are learning. these patterns have been described in terms of developmental s features, or language To some extent, these stages in language acquisition are related to children's cognitive development. For example, children do not use temporal adverbs such as 'tomorrow' or 'last week' until they develop some under standing of time. In other cases, the developmental sequences seem to reflect the gradual acquisition of the linguistic elements for expressing ideas that have been present in children's cognitive understanding for a long time. For example, children can distinguish between singular and plural long before they reliably add plural endings to nouns. Correct use of irregular plurals (such as feet) takes even more time and may not be completely under control until the school years