Update README.md

Author: naoki9911

README.md

@@ -10,7 +10,7 @@ This code includes utf-8 identifiers like α. Therefore, Clang and GCC10 or late
 The default parameter is 128 bit security. Please add -DUSE_80BIT_SECURITY=ON to use faster but less secure parameter.
 
 # FFTW3 Support
-Some environments which does not support AVX2 cannot use spqlios. Instead of spqlios, TFHEpp can use fftw3.
+Some environments which do not support AVX2 cannot use spqlios. Instead of spqlios, TFHEpp can use fftw3.
 To use fftw3,  install `libfftw3-dev` and add `-DUSE_FFTW3=ON` to the compile option.
 
 # Third party libraries