Electronic Journal of Differential Equations, Vol. 2011 (2011), No. 29, pp. 1-25. Title: Construction of almost periodic functions with given properties Author: Michal Vesely (Masaryk Univ., Brno, Czech Republic) Abstract: We define almost periodic functions with values in a pseudometric space $\mathcal{X}$. We mention the Bohr and the Bochner definition of almost periodicity. We present one modifiable method for constructing almost periodic functions in $\mathcal{X}$. Applying this method, we prove that in any neighbourhood of an almost periodic skew-Hermitian linear differential system there exists a system which does not possess a nontrivial almost periodic solution. Submitted August 22, 2010. Published February 18, 2011. Math Subject Classifications: 34A30, 34C27, 42A75. Key Words: Almost periodic solutions; linear differential equations; skew-Hermitian systems.