Examples of Context Free Languages
Here are some of the examples of context free languages


$\{ w \in \{0,1\}^*\mid \ w$ contains at least three ones }
$\{ w \in \{0,1\}^*\mid \ w = w^{R}$ and $\mid w \mid $ is even  }
$\{ w \in \{0,1\}^*\mid \ $ the length of $w$ is odd and the middle symbol is $0$ }
$\{ a^{i} b^{j} c^{k} \mid \ i,j,k \ge 0 $ and $ i + j = k $ }
$\{ a^{i} b^{j} c^{k} \mid \ i,j,k \ge 0, $ and $ i = k  $ or $i = k$ }
$\phi$


Reference : https://web.njit.edu/~marvin/cs341/hw/hwsoln05.pdf