昨日は便利ではありませんでした。

N5 昨日 kinou yesterday N5 便利 benri convenient N5 では dewa then, well, in that case

N3 昨 saku yesterday, previous, hier N5 日 nichi, jitsu / hi, -bi, -ka day, sun, Japan N3 便 ben, bin / tayo.ri convenience, facility, excrement N3 利 ri / ki.ku profit, advantage, benefit

N5 〜です desu Used at the end of a sentence, polite affirmative form, means to be depending on context N5 〜ます masu Used at the end of verbs, polite present or future form, makes the sentence more polite N4 〜ので node Indicates cause or reason in a softer way than kara, connects two clauses, often used in polite explanations N4 〜し shi Indicates multiple reasons or qualities, connects clauses or adjectives, means besides that, and also N5 〜で de Indicates where an action happens, means used, tool, cause, or material depending on context N5 〜は wa Marks the topic of the sentence, indicates what the sentence is about, can contrast with another element, organizes main information