Who to Use Respectively?

'Respectively' means 'separately and in the order already mentioned'. It is used when describing two or more items that refer back to a previous statement. It should only be used if a sentence would be unclear without it. 'Respectively' is typically used to save space.

Do you say respectively or respectfully?

Respectfully relates to showing or expressing respect, with respect meaning "the understanding that something is important." Respectively means "in the order given" and in this case respect is being used to describe how one thing relates to or references another.

Can you use respectively for three things?

Respectively should only be used to describe two or more items. Respectively is not required in example 3, as proliferation was measured using both techniques, or in example 4, as expression of all three genes was quantified using real-time RT-PCR. Therefore, the correct sentences are: 3.