The word "FLU" is a complex word. In order to check the spelling of this word, it is necessary to understand its lexical meaning. FLU - in this case means a viral disease. Accordingly, the test word for it will be "FLUFFY."
GRIPP GRIPPOVAT, GRIPPOKNOW.
By the word GRIP, you can pick up a test word, because here we are dealing with a token, to which we should apply the rule of writing doubtful consonants in the roots of words (at the end and in the middle).
Remember this is one of those first rules that we get acquainted at the beginning of our school life and which is associated with such phonetic processes as assimilation by voicing (voicing) and assimilation by deafness (stunning). For example, at the end of the LEX, POND tokens, as well as in the middle of the words LOVE, TALE, the consonants are stunned, therefore, to select the desired letter: G or K, D or T, B or F, Z or C, we select test words from among related ( of cognate) lexemes or forms of the same words, in which after a dubious consonant sound comes a vowel or sonor: Meadow, Meadow, Ponds, Dam, Bench, TALE, TELL.
But there are words in which stunning does not occur at the end (in the roots), since the pronunciation of their endings coincides with the spelling, for example: BOW, ROD. At the same time, they relate to this rule, since the spelling of the letters K and T also requires verification: ONION BOW, BOW BOW, ROD BAR.
The same applies to the words YOUNG and HAMMER, MUSHROOM and INFLUENZA. In the first tokens of these pairs, stunning occurs, in the second it is absent, but both the first words and the second require verification: YOUNG YOUNG, HAMMER HAMMER, MUSHROOM MUSHROOM, MUSHROOM, INFLUENZA INFLUENZA, INFLUENZA.
Naturally, the spelling of the double consonant at the end of the word you are interested in should be remembered.
There is no spelling in the word that could be checked. The spelling of the word "FLU" just needs to be memorized. Memorize like all other vocabulary words. They are usually constantly indicated in textbooks.
The spelling of the word must be memorized, because the spelling of the doubled "n" is not checked by any rules. These words are easy to write and remember. Look at the "grip", it seems that they wanted to write "mushroom", but we are talking about a disease, so we write and remember "grippa".
First you need to understand what to check.
There is only one vowel in this word, therefore it is not necessary to check it, because it is under stress.
The sounds of r and n are also heard clearly.
So there remains a double consonant that you just need to remember.
By the way, flu does not have a test word, so you will not be able to pick it up. To write it correctly, you just need to remember it.
Conclusion: the word flu is a dictionary word, a word to remember.
Unfortunately, there is no test word for the word "flu". And in order not to be mistaken in spelling, you just need to remember it, or every time you look into the dictionary, which is not always convenient, but anyway, sooner or later this word will be firmly embedded in memory and will no longer cause questions in spelling.
Moreover, if you remember the spelling of this word, then there will be no mistakes when writing cognate words, such as: flu, flu, etc.
There is no test word for the word "flu"! This is a vocabulary word - you can only remember it! 🙂
And it is dictionary because borrowed. The word "flu" came to us from the French language, it is translated as "to seize" ie supposedly the disease quickly captures a person, quickly becomes ill with it. But, I must say that in the Russian language there is a similar word, just like it was called before the flu. This word is "wheezing". You understand why - because of the characteristic cough that occurs with a cold.
The word "FLU"is a masculine noun. In order to avoid mistakes when writing this word, it should be learned, well remembered, since it is a dictionary word.
The word "" influenza is very often written on stands in schools, clinics and hospitals. And since it often catches the eye, then how it is written by itself is visually remembered.
Influenza is such a painful condition of a person, which is accompanied by a high body temperature, cough and runny nose.
There are a number of words in the Russian language that cannot be checked. What exactly can we check? Unstressed vowels, if we pick up a single-root word where the desired vowel is stressed (water - water). Voiceless or voiced consonants, if we pick up a single-root word where the required consonant is clearly audible, for example, next to a vowel (pond - ponds).
Words whose spelling is not governed by any rules or not verified by any other words, just need to be learned. If in doubt, contact dictionaries to the full assimilation of their spelling. The word flu refers to such words. It is borrowed from French, it is written with two letters p, because the two letters p were in its original spelling. There is no logic for the Russian language, it remains only to remember.