いかにも

1. 1Emphasizes that someone's appearance or behavior strongly matches the typical image of a type of person.Ex. 1
2. 2Stresses that something is characteristic of its kind or season, often with 名詞＋らしい.Ex. 2
3. 3Used alone as a reply meaning 'indeed' or 'quite so' to affirm the other person's statement.

A common adverb in both speech and writing that highlights how typical or characteristic someone's appearance, behavior or a situation is. Unlike どうやら or とみえる, which mark the speaker's inference from evidence, it stresses how strongly something fits an expected image. The standalone reply 'いかにも' sounds rather stiff or old-fashioned.

• さもN1「さも」 is bookish and must pair with 「かのように」 or similar — it never stands alone and has no response use. It often implies something is 'put on' and may not actually be true, though it can also simply stress that the manner is obvious; use 「いかにも」 to praise something as genuinely typical and true to its name.
• どうやらN2Both often pair with 「らしい」 and 「そうだ」, but 「どうやら」 means 'it seems / apparently' based on signs and carries uncertainty, while 「いかにも」 stresses that something is perfectly typical and really does look the part, so they are not interchangeable. 「どうやら」 also has a separate sense of 'at last / finally'.
• さぞN1「さぞ」 puts you in another's shoes to imagine the depth of their feelings or situation, usually paired with sentence-final 「だろう」 or 「ことだろう」 and carrying a tone of sympathy, consideration, or exclamation. 「いかにも」 instead evaluates an appearance or trait as highly typical and can also serve as a response, so the two cannot be swapped.
• っぽいN3「っぽい」 is a colloquial suffix that, in its 'seems like...' sense, means having a certain trait, often with a negative nuance, and the thing need not truly be of that type; 「いかにも」 is an adverb that usually pairs with 「らしい」 and stresses being true to its name, so the two cannot be directly substituted.
• とみえる / とみえてN3「とみえる」 attaches to the plain form and means 'it seems...' inferred from signs, with an objective, written-style tone; 「いかにも」 is an adverb that subjectively stresses a perfectly typical appearance, often pairs with 「らしい」 and 「そうだ」, and can also serve as a response — they are not interchangeable.

「いかにも」 subjectively stresses that something looks perfectly typical and lives up to its name; it often pairs with 「らしい」 or 「そうだ」 and can also stand alone as a response. The others differ: 「どうやら」 and 「とみえる」 infer 'it seems' from signs rather than judge typicality, 「さぞ」 empathetically imagines another's feelings (usually with sentence-final 「だろう」), 「さも」 is bookish, requires 「かのように」 and often implies pretense (or just an obvious manner), and 「っぽい」 is a colloquial suffix for 'having a trait', often derogatory, without truly belonging to that type.