Question: Using this preamble:

```
\documentclass[pdftex,11pt,a4paper,openany]{memoir}
\usepackage[brazil]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{indentfirst}
\usepackage{latexsym}
\usepackage{amsmath,amssymb,amsfonts,wasysym}
\usepackage[pdftex]{graphicx}
\usepackage{wrapfig}
\usepackage[left=3cm,right=2cm,top=3cm,bottom=3cm]{geometry}
\usepackage{color}
\usepackage[dvipsnames]{xcolor}
\definecolor{darkgray}{gray}{0.3}
\setcounter{secnumdepth}{3}
\setcounter{tocdepth}{3}
\usepackage[pdftex, colorlinks=true, linkcolor=darkgray, citecolor=blue, urlcolor=blue]{hyperref}

```

TexMaker gives this error message:

```
! LaTeX Error: Command \newfloat already defined.
Or name \end... illegal, see p.192 of the manual.

```

Where is the problem?

Answer: 
You should use a package like `enumitem`. The package allows to modify the `item` by a key-value-syntax.

```
\documentclass{article}
\usepackage{enumitem}
\begin{document}
\begin{enumerate}[label=\textbf{\arabic*},start=0]
   \item First item
   \item Second item
   \item Third item
\end{enumerate}
\end{document}

```

![enter image description here](https://i.stack.imgur.com/2xSBp.png)
By using `enumerate` package you can also use this command.

```
\documentclass{article}
\usepackage{enumerate}
\begin{document}
    \begin{enumerate}[\bfseries a.]
        \item one
        \item two
        \item three
    \end{enumerate}
\end{document}

```