An effective way to signal a contrast within a sentence is to use a signal word, such as

Question

also.
same.
similarly.
however.

Answer 1

The effective signal word for indicating contrast within a sentence is "however." This word is used to introduce a statement that contrasts with or opposes the previous statement. The other words listed—"also," "same," and "similarly"—are typically used to indicate agreement or addition rather than contrast.