e.g. Write the small letters in the alphabet continuously putting together.

Is this expression correct? Do you have some more good expressions?

I think you mean,

Write the small letters OF the alphabet in the correct order.

You could also say,

Write the lower case letters in alphabetical order.

Write the small letters in the alphabet continuously putting together in Italic script.

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What about the expression above?
Writting the letters with the pen on the paper is called what?

We say "letters of the alphabet."

You should say, Write the small letters of the alphabet, putting them together in italic script.

The expression you provided is not correct. In the alphabet, the lowercase letters would be written individually and not continuously put together.

However, here are a few examples of expressions that can be used:

1. Write down the lowercase letters of the alphabet consecutively: The correct answer would be "abcdefghijklmnopqrstuvwxyz".

2. List the lowercase alphabet in a series: The correct answer would be "a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z".

3. Provide the sequence of lowercase letters in the English alphabet: The correct answer would be "a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z".

I hope these examples help clarify how to correctly express the lowercase letters in the alphabet. If you have any more questions or need further examples, feel free to ask!