Question

knows 4000 words approximately and used of dictionary , spelling and physical grammar.​

Answer 1

• A dictionary is a listing of words in one or more specific languages, often arranged alphabetically (or by radical and stroke for ideographic languages), which may include information on definitions, usage, etymologies, pronunciations, translation, etc. or a book of words in one language with their equivalents
• Spelling Helps Reading. Learning to spell helps to cement the connection between the letters and their sounds, and learning high-frequency “sight words” to mastery level improves both reading and writing.
• The term grammar is often used in a rather different sense. It may be used more broadly to include conventions of spelling and punctuation, which linguists would not typically consider as part of grammar but rather as part of orthography, the conventions used for writing a language.