No. The word "that" is not ever a preposition. It is only an adverb when it modifies an adjective or adverb (that tall, that badly) and means to some extent.
No, it is not a preposition. Usually is an adverb.
No. Yes is not a preposition. It is an adverb or noun (reply).
No, it is not a preposition. Furthermore is an adverb.
No. Frequently is an adverb. And it cannot be a preposition.
No. Lastly is an adverb. It cannot be used as a preposition.
No. Almost is an adverb. It is not used as a preposition.
No, it is not a preposition. Usually is an adverb.
No. Yes is not a preposition. It is an adverb or noun (reply).
No, it is not a preposition. Furthermore is an adverb.
No. Frequently is an adverb. And it cannot be a preposition.
No. Lastly is an adverb. It cannot be used as a preposition.
No, it is not a preposition. It is an adverb.
Yes it is a preposition. It is also used as an adverb and less frequently as a noun.
No, the word "from" is a preposition. It cannot be used as an adverb.
The word with is not an adverb; it is a preposition. The word "without" may be an adverb (e.g. to do without, where no specific object is used).
No, "though" is not a preposition. It is commonly used as a subordinating conjunction or an adverb in sentences.
No, "afterward" is an adverb, not a preposition. It is used to indicate time in relation to a past event.