A differential form $\alpha$ of bidegree $(p,q)$ on an open subset $V$ of ${X^{\rm an}}$ is given by a covering $(V_{i})_{i\in I}$ of $V$ by tropical charts $(V_{i},\varphi_{U_{i}})$ of ${X^{\rm an}}$ and superforms $\alpha_{i}\in A^{p,q}({\rm trop}_{U_{i}}(V_{i}))$ such that $\alpha_{i}|_{V_{i}\cap V_{j}}=\alpha_{j}|_{V_{i}\cap V_{j}}$ for every $i,j\in I$. If $\alpha^{\prime}$ is another differential form of bidegree $(p,q)$ on $V$ given by $\alpha_{j}^{\prime}\in A^{p,q}({\rm trop}_{U^{\prime}_{j}}(V_{j}^{\prime}))$ with respect to the tropical charts $(V_{j}^{\prime},\varphi_{U^{\prime}_{j}})_{j\in J}$ covering $V$, then we consider $\alpha$ and $\alpha^{\prime}$ as the same differential forms if and only if $\alpha_{i}|_{V_{i}\cap V_{j}^{\prime}}=\alpha_{j}^{\prime}|_{V_{i}\cap V_{j}^{\prime}}$ for every $i\in I$ and $j\in J$. We denote the space of $(p,q)$-differential forms on $V$ by $A^{p,q}(V)$. As usual, we define the space of differential forms on $V$ by $A(V):=\bigoplus_{p,q}A^{p,q}(V)$.