Let π : T × X → X, written T π X, be a topological semiflow/flow on a uniform space X with T a multiplicative topological semigroup/group not necessarily discrete. We then prove:• If T π X is non-minimal topologically transitive with dense almost periodic points, then it is sensitive to initial conditions. As a result of this, Devaney chaos ⇒ Sensitivity to initial conditions, for this very general setting.Let R + π X be a C 0 -semiflow on a Polish space; then we show:• If R + π X is topologically transitive with at least one periodic point p and there is a dense orbit with no nonempty interior, then it is multi-dimensional Li-Yorke chaotic; that is, there is a uncountable set Θ ⊆ X such that for any k ≥ 2 and any distinct points x 1 , . . . , x k ∈ Θ, one can find two time sequences s n → ∞, t n → ∞ with s n (x 1 , . . . , x k ) → (x 1 , . . . , x k ) ∈ X k and t n (x 1 , . . . , x k ) → (p, . . . , p) ∈ ∆ X k .Consequently, Devaney chaos ⇒ Multi-dimensional Li-Yorke chaos.Moreover, let X be a non-singleton Polish space; then we prove:• Any weakly-mixing C 0 -semiflow R + π X is densely multi-dimensional Li-Yorke chaotic.• Any minimal weakly-mixing topological flow T π X with T abelian is densely multidimensional Li-Yorke chaotic.• Any weakly-mixing topological flow T π X is densely Li-Yorke chaotic.We in addition construct a completely Li-Yorke chaotic minimal SL(2, R)-acting flow on the compact metric space R ∪ {∞}. Our various chaotic dynamics are sensitive to the choices of the topology of the phase semigroup/group T .