"Take into account" is used as a verb phrase, typically in the imperative or present tense. It is a command or suggestion to consider something.
Examples:
* "Please take into account the deadlines when scheduling your appointments."
* "We need to take into account the weather conditions before making our decision."
"Taking into account" is a participial phrase that acts as an adjective or adverb. It modifies a noun or verb, indicating that something is considered.
Examples:
* "Taking into account the recent economic downturn, we need to revise our budget."
* "Taking into account all the available data, we can conclude that the theory is sound."
The choice between the two depends on the context and the intended meaning. If you want to give an instruction or suggestion, use "take into account." If you want to describe something that is considered, use "taking into account."