The Emacs commands for manipulating sentences and paragraphs are mostly on Meta keys, like the word-handling commands.

M-a

Move back to the beginning of the sentence (backward-sentence).

M-e

Move forward to the end of the sentence (forward-sentence).

M-k

Kill forward to the end of the sentence (kill-sentence).

C-x DEL

Kill back to the beginning of the sentence (backward-kill-sentence).

The commands M-a (backward-sentence) and M-e (forward-sentence) move to the beginning and end of the current sentence, respectively. Their bindings were chosen to resemble C-a and C-e, which move to the beginning and end of a line. Unlike them, M-a and M-e move over successive sentences if repeated. Moving backward over a sentence places point just before the first character of the sentence; moving forward places point right after the punctuation that ends the sentence. Neither one moves over the whitespace at the sentence boundary. Just as C-a and C-e have a kill command, C-k, to go with them, M-a and M-e have a corresponding kill command: M-k (kill-sentence) kills from point to the end of the sentence. With a positive numeric argument n, it kills the next n sentences; with a negative argument -n, it kills back to the beginning of the /n/th preceding sentence. The C-x =DEL= (backward-kill-sentence) kills back to the beginning of a sentence. The sentence commands assume that you follow the American typist's convention of putting two spaces at the end of a sentence. That is, a sentence ends wherever there is a ., ? or ! followed by the end of a line or two spaces, with any number of ), ], ', or " characters allowed in between. A sentence also begins or ends wherever a paragraph begins or ends. It is useful to follow this convention, because it allows the Emacs sentence commands to distinguish between periods that end a sentence and periods that indicate abbreviations. If you want to use just one space between sentences, you can set the variable sentence-end-double-space to nil to make the sentence commands stop for single spaces. However, this has a drawback: there is no way to distinguish between periods that end sentences and those that indicate abbreviations. For convenient and reliable editing, we therefore recommend you follow the two-space convention. The variable sentence-end-double-space also affects filling (Fill Commands). The variable sentence-end controls how to recognize the end of a sentence. If non-nil, its value should be a regular expression, which is used to match the last few characters of a sentence, together with the whitespace following the sentence (Regexps). If the value is nil, the default, then Emacs computes sentence ends according to various criteria such as the value of sentence-end-double-space. Some languages, such as Thai, do not use periods to indicate the end of a sentence. Set the variable sentence-end-without-period to t in such cases. Even though the above mentioned sentence movement commands are based on human languages, other Emacs modes can set these command to get similar functionality (Moving by Sentences).